Transcript for:
Current Electricity Overview

Welcome all of you on Ashu Ghai 11th 12th Where teachers means I am Ashu Ghai, you love And I teach with both my mind and my heart. The proof of teaching with the mind is that you I am also teaching physics here. I am also teaching chemistry. So brother welcome welcome welcome the best forest The studies that were going on in the shot till now I had studied electrostatics but now I have come are on electrodynamics but from that First I would like to talk about this Best one shot with question on the channel We have put the answers in chemistry solution is very good and interesting then put it I have also given electro chemistry to all of you We secured first position in Request Pay and Physics Both meanings of chapter electrostatics One shots of first and second chapters I completed it. Now it is the turn of Physics third One shot of chapter i.e. Current Electricity of. but maybe a lot of you Kids must have seen the one shot of this chapter First it could be mine or someone else's or You have come here to revise. so one Would I like to give you advice? In this chapter, we Is divided into two parts. First We did it in about 1 hour in each part. It is written here 30 minutes. then 1 hour 30 minutes 1 hour 1 hour 30 minutes per you If you go then we will tell you that part one is over. Went. We have got the questions asked. to you all You know, we can get the question answered in one shot have been. You know it, right? and that is also excellent Question. So where from where in part one till? You will skip this one shot right? If you go at 1 hour 30 minutes then it will take 1 hour 30 minutes You will find me asking questions there. So if you understand the whole chapter then you can get 1 You can go and ask questions at the time of 1 hour and 30 minutes yes. This is the previous topic. Because you all I know, it's a very basic one. same as 10th Is. But if you don't get it then I would request you all to watch it. After that the next half is the second half which is ending. I have written it for 2 hours At 2 hours 39 minutes. So 2 hours 39 minutes I have got the questions of part two done. This means dividing this chapter into two parts Given. Part one was taught and then questions for 1 hour In 30 minutes. Then he taught Krachoff Law. and hey Brother, this is a very important thing. After that Then I got his questions asked. critch of law Even while teaching the question of law Have got it done. I got one or two done later also. So if you want to go to the questions, here it is Time stamp. But I want to see the full one shot. So here it is in front of you. Coach if you've seen this one If you have seen the shot before then please see it again I think there is no need. a few topics If you are stuck somewhere then skip it Skip and see. Son, time it correctly Utilize it. but if you first see If you are studying and want to revise the whole chapter then You won't get a better one shot than this. come on start Let's do a one shot. yes kids in the video A small but very important thing before moving on I am going to talk about something important. Our Batch 2.0 has been launched in which we work daily Everyone is going to come and teach you live Subject. It includes classes from 9th to 12th You will find all the batches on our app. Along with Science, there is Commerce, NDA and Batches of CUET are also available. Then What are you waiting for? given in the description And first pin the link given in comment Click and become a paid batch of Science and Fun Part of. Remember all the discounts In paid batches, it is available for a limited time only It is valid. Now let's move ahead in the video. Current Electricity Still Read How is it going to be different from both the chapters? So the first and second chapters that we had Both of them had chapters of electrostatics, that is of electrostats. That means the charge is ours Whoever was there, he remained at rest. But from now on Our charge will remain in motion going forward. From here will begin. From now on, the charged particle it has to start living in our motion are going to. Now as soon as we start here We will read two things today. Electricity or electric current. Both We will take different things and study them together. The The point is that from now onwards our charge will be will come into motion. start moving will give. The first half hour is very basic stuff Will collect. main one shot of half an hour It will start later. I am not saying that That skip 1/2 hour. because its basic Things will have to be collected. then we read it We will start with what comes in our exam. So the first word that comes to us is What is electricity? Electricity What happens? So electricity is a form of energy which is created whenever a charge Particles come into motion. so whenever Charged particles are running in one place are going from one place to another. So that Any energy that is produced during It is called electricity. i.e Electricity is a form of energy which Due to flow of charges will be made. Isn't it? And What do we call the flow of charge? Are? Electric current. so from here The definition of electric current also begins Is. There are two definitions of electric current. The one in English that says The Flow Of charge is called current. Now the current which is a is an English word. The current one is now is an English word. Current means flow Is. Like wind current means flow of air Happen. Ocean current means the water in the ocean It flows. Thermal current means the flow of heat Happen. Similarly, water current means water is flowing somewhere. Used to be. just like electric Current means flow of charge. But if we have to calculate the electric current If you have to give mathematical definition then how much charge passes through a conductor per unit time i.e. We are passing by in these one second Let us call it electric current. Since childhood I have been reading. So mathematics since childhood what i mean to say is 10th class and Somewhere in schools, somewhere in books Even before that. then the electric current What is the definition? Electricity is energy which will come from the flow of charge. But Electric current which we represent by I We do. This is how much one charge is Going perpendicularly from the conductor. Meaning Going on unit time. Isn't it? and if we're saying dq charge is going delta In time t, if the delta Q charge is going If delta t is in time then the formula for current is deltaQ will be /delta. and all of you Know if the charge is going too low This is a matter of respect for a very short time If we do this then we will also get dq / dt. That means that Current is the rate of flow of charge i.e. How much charge is flowing in this given time. So here we are on the first screen, The formula comes here. Now the current SI unit I told you first half hour It will be very basic. So the SI unit of current is What happens? because we have current The formula is charge or delta T right? How You can talk as you wish. q / t delta q / delta t dq / dt is the same thing. so according to that The si unit that we make is what are you making brother? then the charge is Coolum. time is of seconds then on coolam Seconds. But you all know a great In the name of the human being Andre Marie Ampere I think there is no child with this name Those who haven't heard, they must be in 12th. In the name of Andre Marie Ampere Ampere unit was kept. Isn't it? Now you also Do you know when 1 ampere current is generated? So when 1 coulomb charge passes, every in sec if from inside a conductor 1 If coulomb charge is passed in 1 second then How much current will be generated? 1 ampere. So 1 ampere Which current is this? A current which is will be formed through the conductor when in one second one Coolam charge will pass. Ok? Now we talk conventional current and electronic Current. What is this thing? a little carefully I will listen. It's basic. It's very basic. See, When we made the current study we saw that we don't even need the direction of the current Is. Cannot read current without direction Was going. All two currents are vector quantities no, he has direction but still That is not a vector quantity. But we Its direction had to be made. Now all of you Children know that electrons are made of wire Running from inside to create current. But electrons were discovered by J.J. Thomson ji and electricity was created much before that It is being made from. So we first Conventionally the direction of the current was made the positive terminal negative Terminal. Take care. and that makes us Pass conventional current. There was nothing like this before Conventional Current etc. First, just the current There was current. I'm telling you to have some patience Please Keep. current was current and which was conventional current Now that flow is positive. Two negative because it was believed that the wire Positive charge must be flowing inside. I had accepted that. Such was the convention. As such It was assumed that there is a direction positive to negative due to in a way Positive charges. due to in a way Positive charges. But when brother J.J. Thomson, Rutherford all of them discovered the atom Gave structure and opened our eyes. We Understand that actually it is a race There are electrons. what will you do now Brother? So we said, look friend, we Had done a lot of studies. If we consider positive to negative then we have The direction of the current was not changed. We said let's do this. They believe that where Electrons will flow. The current is always We have been believing that there will be an opposite flow. So the electronic current is opposite happens i.e. now if the electrons run So where will the electrons run from? These I have the positive terminal. I have this It is negative. So brother the positive will run. will be attracted from positive to negative will be. but negative charge means actually The electrons running in it are negative from goes to positive. So we did the current Did not change the direction. because if We would change the direction of the current. If If we change the direction of the current then what happens? So it would have been like this: brother ah the rest I had to change my studies. So we didn't tell him Let it remain that way. remember that so The electronic current will be negative two Positive. Due to negative charges. and later It was announced that wherever Bhaiya tested negative The charge will flow and the current will flow opposite to it. Where the electron is opposite to the current will be. These upcoming chapters, especially the fourth It will be very useful in the chapter. Remember this. If Electrons are running east, so the current The West will run. if the electrons are racing North, then the current will flow south. If If electrons are going inside then current will be generated Outside. Keep this in mind. So any two There is no current type. It's just a direction, It's an emotional thing. Come on come. Now let's talk About electro motive force. again Electromotive force is nothing new. Electromotive force means voltage Is. There is only potential difference. just this How is it different from voltage or potential difference? Is? Come let us understand this. Ok? We have There is a circuit here. Let's accept it. Ok? how is this circuit bro? Isn't it? There is something like a bulb fitted here Is. This is a bulb we have. This is the switch we have. Ok? As soon as I turn on the switch, you all know that this bulb will burn and current will flow From here to here. Everyone knows. Is it okay? Current will flow here. Current will flow. Now You tell me if you are assuming this That electrons are running inside it. So You all know that electrons are negative will go out will go out will go out We will go and end on a positive note. but his What next? If all the electrons race from the negative What will happen if the result is positive? The circuit is not complete. If all the all the electrons race from the negative If you test positive then what next? The circuit is then Consider it complete as if you have put it in a water tank There is a lot of water filled. default full Accept it has happened. Ok? or took away Let us go. Accept it. Now you opened the tap. Sarah's You filled all the water in your bucket. I took a bath and did whatever I could. Now when all this The water comes down into your bucket. now when until you put the water back into the tank If you fill the water it will not come down. So if you If you want a continuous flow then You will also need to send water to the tank and Then it will come down from the tank also. This is the process Is. If you only use tank water If you keep doing this, the tank will get empty and The flow will stop after a certain level. Similarly, if the charges are negative Only positive results continued. electrons Kept going from negative to positive. Then How will the current flow? so but now How do electrons go from positive to negative? Will you go? Because it is a bit difficult to go there It is difficult for him so push them we will have to kill it because the electron has charge It is negative. They go lower Higher than potential, not lower than higher Will be able to go For that we need electrons Lifting and lifting and pushing from positive to negative Will have to kill. that a battery or cell does Is. So if a cell or battery does how much work Used to be? transfer a charge from one terminal to another How much work to take to the terminal have to do it but it is called unit charge are the emf. That is, suppose I have two points in I talk between two points and If I take out the work done upon charge then this will be called the potential difference second Chapter. But if you go from one terminal to another talk between the terminals and I take out the work done upon charge then this What will it be called? EMF ie Electromotive force. I have it here There is a cell. Is it okay? I have it here There is a cell. Now every cell that is there has a positive There is a terminal. Take a sale na. As an example, take a sale. it remained. Here it is. Oho. Yes. Here's a sale, okay? now this cell I am positive here, I am negative here. Now if from positive to completely negative, or Negative to positive. depends on who There is a small charge. but from one terminal to another How much unit charge per work done at the terminal Is. This is called EMF. But here I There is a wire installed on it and here, like this I just put cells in the mic. So Any two points like if I have put them here A wire has been installed. There is a wire attached here. So from this wire between this point and this point How much is the unit charge per work done? This We call it potential difference. i.e Both are the same things. something different about them Not there. We give you the charge in just one go Let's talk between the points. In electric potential, we measure charge Brought it from Infinite. there is a terminal There is a conversation from another terminal. Or The matter is against the potential. Ok? electromotive force of a source of a Source. First of all, this is for the source only It is defined. Two points in the middle of a circuit It is not for. can be defined as the work Done of the source in taking a unit positive charge from lower potential to higher Potential. Now with respect to positive charge This definition is written in . positive Charge goes automatically from higher to Lower. You have to take it to the lower Higher than that, right? So how much work to do Will it need? We will call it emf. to the emf We will represent with E and what is this will be? Unit Charge on Work Done. hey sir this We have seen the formula before. Yes, I told you it is all old. Is. Just what is the difference? I will say it again Because son you will say sir why so late We are putting it in this topic. it is necessary to put Is. It became weak. You will not understand further. This is the work of the entire circuit. whether you Go from negative to positive, whether from positive Negative. You only know about plus and minus There is going to be a difference going forward. If you are 500 Joule does work, take water from the motor to the tank to go and even to bring it down from the tank It will be 500 joules only. Energy Can Nader B Created nor be destroyed. Is it okay? So this is the potential difference. but this This is its maximum value. because these are whole is of the circuit. So tell me now in the comment section I should tell you with a time stamp that yes sir, write Can you? No sir, I can't write. tell this The time stamp would be around 14-15 minutes. Tell me with time stamp whether this definition is correct I can write the emf of that is maximum Potential Difference of a Circuit. to understand For this, can it be written such that the emf which is that is the maximum of potential difference There is value. I can definitely write. Take it sir He is making us talk about the SI unit. Are you joking bro? SI of emf Please tell me the unit. Why should I tell you? yes, address It is there, everyone knows it. Let us go. Let us go. Work Done What is the unit of? Joule. of charge It is cool. So what happened? On Joule Coulomb. Alexandrolta is the same brother. Beans Yes brother, it is beans. 1 volt is also added there It was defined. need to do here No. I think it's beans. let's get it done now Went. Now let's talk about this chapter About something very important. Which is Ohms law. and then a little bit Let us see the demonstration of Ohm's Law. Oms You have studied law in 10th only. ohms law says if you have a conductor, you can measure his temperature and if you you keep the dimensions constant, the dimensions means its length, its area of ​​cross sections etc. if you want to read all these If you keep constant then in that case this I will remove it. So in that case, as much as The more you apply the potential difference on it the more you apply EMF, the more The current will flow inside it. according to Ohm's Law, The Current Flowing Through a Conductor is directly proportional to potential Difference applied across its ends. Very It's a matter of common sense. Now we have grown up. So it is a matter of very common sense that how much you You are making the current flow in the circuit. These It will be directly proportional. How much voltage emf potential difference you I have applied. These are almost the same things. There is a small difference. But what is the condition that You need to keep the temperature and dimensions constant. Have to keep it. then V is proportional to I Will go. Now if that is the case then here we have to Remove the sign of the proportional and apply equal If it is then you will have to put a constant here. Then V Is equal to what will happen? I am R Will go. Or it will become RI. Here, we call R What do people say? Constant speaks Which is resistance. I have told you guys A very important rule of maths has been taught. If you haven't learnt it then learn it again. Whenever anybody The constant appears in an equation The constant does not change in that equation You can make these short r by changing some things. can't change by changing v and I Because it is a constant in this equation. We can change R in other ways But you can't do it by changing V and I. Sir, this R was a constant. You have read R Why didn't the resistance speak out? of the resistance It means obstruction. yes this is an obstacle Is. How is this obstruction? How is this obstruction? Because v = IR formula has come. Here What is the formula of I from? I of I of The formula V/R has arrived so if you pay attention to it carefully If you look, I and R are inversely related to each other. They are proportional. That is, if R is large then I It will reduce. How will you increase R sir? V and I You can't do it by changing it. know today This has to be read in the entire one shot. will read that R how to change something. Assume the butt If you increase R then I will decrease. So R is something that allows the current to flow Prevents it from happening. just behind definition I will write about it. This is an obstacle. prevents it If there is obstruction then it is called resistance. Correct is it yes? It is written here that this We call the constant R, R means Resistance and it is purely independent. Brother, the world should turn upside down. V and I R cannot be changed by changing it. Ok Yes? Now let's talk a little about R. But once again we follow this law of Om ji We are also going to provide proof in this chapter. But What did Om ji say? At Constant Temperature and dimensions. Current Flowing through a circuit or conductor is directly Proportional to Potential Difference Applied Across its ends. how much on its corners Has potential difference been applied? R we have It became constant. Now about this R Let's talk about it. We named R as resistance. why did you give it? because this is a property which prevents the current from flowing. Like a ball falls on the road due to friction It will stop. stop pedaling on the bike It will stop due to friction. like that every Every substance in the world is more than any other substance Any less obstruction to the flow of current in being. We call that obstacle resistance. They say. You can say in your mind that this There is friction in the circuit in a way. Is No? So you can say what is resistance? Property Property of substance Which Rests Gave Flow of current property of substance which is related to current resist the flow i.e. due to which We should not consider that property as there is no current flow. It is called resistance. So the resistance The formula has come down to us V / I backwards Using the equation and from here, if Let me talk about its SI unit So the unit of V is volt current If it is ampere then what happened to volt brother Ampere you all know its another unit it also happens and that is Om, right brother and When does 1 ohm resistance come to 1 ohm When does resistance come into play when you connect a 1 volt Apply potential difference and 1 ampere Ampere current should flow. i.e. at 1 volt If 1 ampere current is flowing then the entire of the circuit which is the total circuit The resistance will be 1 ohm. Correct Is? Correct? Now depend, now see which ones Does it depend on? I have just read it. V And it does not depend on I. this is for sure Is. This is for sure. then on whom would he do this Is? I will read this only. Come. Come before that. from that First let's talk about Let's make a graph of this. very important The graph is. There are full chances that you In the paper You will find a question above this graph. There are full chances. Here is V. Sorry My bad. Here is V. Here is I. oh ho ye How did it become white? Never mind. Yes. Now Are V and I proportional to each other? and I If I put zero then V will become zero. Its This means that the graph will start from the origin. Now because both are directly proportional because both are directly connected to each other If it is proportional then the graph will go straight. And you Everybody knows about it, if I find the slope I will give you the slope, I will remove the slope, then I will get V/I Will go. What is V/I and V/I from its slope? Resistance. So how does the question come up? Two I will give you the graph. Tell me whose will you say Is the resistance high? which has higher slope Yes its resistance is high. Isn't it brother? Isn't it brother? Isn't it brother? Ok? but never You will remember your 10th class sometime. all of you It must have been very moe-moe. I am absolutely sure Is. Many of you kids had Momoi Is. If yes, please post in the comment section Write that yes sir we have had moi-moi. Sometimes even Kabhar C enjoys like this and Here I gives and here V gives Is. Now the graph remains the same. because Both are proportional. The only difference would be that That is brother, the slope here is I / It becomes V. and because of the i/v The slope becomes 1/r. so in that case The one which has higher slope has lower r goes. It becomes the opposite. so take care Don't you get tempted. Done? Let's move on from First let us understand Ohm's Law a little bit Experiments will then proceed from small scale. Now Let us look at Ohm's Law once. Now! If you remember we had a sale on this Had imposed it. Now a cell if we have approximately If it is about 1.5 volts then we have one cell It comes and gives this reading, it is approximately Gives 1.5 amperes. A cell is approximately Gives a reading of around 1.5 amperes. but if I were to talk about it there, if I If I put two cells together, will one cell is 1.5 volts and two cells we have about 3 It will become volt. If I go by the assumption That both the cells are perfect and new. So If I connect the two cells together I will apply it. one second, one hit from here I gave it to you, I placed one here. one more second If I put these two together you can see The current may be around 3 amperes Already happened. What was the current earlier and you, oh brother This is probably something bad. so almost almost The current has reached 3 amperes. A little more than 2.5. then on a sale The current was 1.5. But if you apply it on two then it will be 2.5 or It's around three. which means As the voltage increases the current will increase and Ohms law also states that the voltage By increasing the current, so here you come Guess your Ohm's Law has become a little clearer will be. Now we have talked about V and I They are proportional to each other. But this thing It is pending which resistances will be there Depends on the factors. So the total was The resistance of a substance to four things It depends on the pay. The first thing is the length Or say the length of the conductor. Joe Resistance It happens directly along the length of the conductor It is proportional. That is, if the length will be more i.e. if one conductor is more If the length is large then its resistance will be It will be even more. If I make it very simple If I explain it in words then you will accept my There is a wire nearby which is 5 meters long. Ok No? Now it has a certain resistance, so The resistance of 10 meter wire in the same It will double. 20 meter wire is there It will become four times. The Point Is Jitney More length will increase the resistance The obstruction will increase that much. That is, if I a long wire all other factors here is constant. Area, temperature and everything else Things are constant. just one at a time Factors are changing it. so length If it increases then the resistance will increase. We will now look at all these and combine them as well do. But the second factor comes first Are. And that is the area of ​​cross section. Now What is the area of ​​cross section or area? Is there any difference? then the area of ​​cross section It means from how many areas our current which is or the electrons which is or the charge which They are entering or exiting. Value Let's take this, I have a wire. Isn't it? so this is what happens this is what happens this part We call this the area of ​​cross section. If the wire is thick then the area of The cross section will be larger. if over there There is a thin wire, let's say there is a thin wire So the area of ​​cross section will decrease. So Resistance with Area of ​​Cross Section How does Verry work? I have been studying since 10th class have been. This is the topic of 10th class which This area of ​​cross is resistance It is inversely proportional to the section. Isn't it brother? Area of ​​cross section Inversely means the greater the area of Higher the cross section, thicker will be the wire, The resistance will reduce that much. i.e Resistance is inversely proportional to Area of ​​cross section. So these two Which of the wires has higher resistance It is going to happen according to you. So these two Its resistance will be less than that of the wire Because it is thick and its resistance It will be more. assuming that all the rest The factors are constants. That means their The length is equal. Their material is equal. Their temperature is equal. Etsetra Etcetra. Now these two factors are clear Are visible. But what about L and A? in a manner? The resistance is from someone else It would depend on the thing as well. so the answer is Yes, the biggest factor is pending, that is Nature of Material. So on the nature of material will also. But right now if I were to Combine ah sorry should I combine these two Combining first and second so I like R is Proportional to L/A will be available. So brother L K happened directly and A happened Inversely. Now from here, if I take the proportional If I remove the sign of and apply equals then I have to put a constant here. Whose name is Yahan Pe Abhi Ro. of this symbol The name is Ro. But what is this cry? Ye Cry what is it? is it an obvious thing Resistance depends only on L and A Is? No, it depends on four things Majorly l a nature of material and temperature. So these two factors are the nature of material And this row represents temperature to them Is. What is the name of this cry, brother? ISRO. O! Yes, this is a deep topic. The meaning of this cry is these What is the name of the cry? of this row means these ones The name of the cry is resistivity. Resistivity. Resistivity is also resistance Just as it is. This also happens due to the flow of current It just stops me. But it depends on two On things. One is how does the nature of material work? How Its value for the material is high, How is short for? Everyone will read it. and there is one This depends on the temperature. of both I have to read about it. only in 10th and 12th What is the difference that we did not study this in 10th was that this was for the nature of the material What is the value for which material his? And I hadn't even read that, that means How does it change when the temperature changes? Is. This is the difference. Plus we get Ohms Law Have to prove it also. so many diff Are. Many new things will also come. butt yes This is what we are reading right now, the first half hour It's almost 10th. So we have the formula for R Roll/A comes here. yes here it is Pay again is a basic idea. Now if Let us talk about SI unit of Resistivity depends on will talk about the nature of material and temperature How are you? But before that we have r The formula of ROL/A has been arrived at according to that From this we have the formula for rho * in a / l so from here if I its si If I talk about the unit then unit of becomes ohm area meter squared becomes meter If meter to meter gets cancelled then the unit Does it come brother, does its ohm meter come if it is there then what is the unit brother its om The meter comes, that means we measure the resistance We used to measure resistivity in ohms but we call it resistivity Will measure in ohm meter. It's a very basic thing. Let's move ahead. Now this resistivity The value is these conductors, insulators, Semiconductor means in easy language So how will it depend on the nature of the material? It is clear that the R and the Ro are It is directly. Meaning, the value of row increases will increase R. Now the insulators that are The resistance would have been too much for them Is. This is common sense. more obstruction it occurs. That is why current does not flow. So That is why there will be a need for insulators The value of will also be very high. Who conductors inside them very easily The current goes off. So I cried for them The value will be very low. right there semiconductors and alloys, both of which There are different things but I cried for them The value will be slightly higher than the conductor But it will be less than the insulator. come on exact Let's also talk about value. conductors having very low resistivity Is. How many? Powers of 10 - 8 to the power of 10 -4 It is obvious. in ohm meter The value is written. Isn't it? right there The value of insulators is very high. 10's Even more than Power 8. 8 to the power of 10 or Even more than that. and that's where semiconductors Or Eloise both are different things. But the value Almost beans. Powers of 10 - 4 to the power of 10 It is in the range of six. So enough from the conductor It is more but much less than the insulator. So you can define them like this also. Do we need to remember these values? Yes, You have to remember the value of resistivity. Now this depends on the nature of the material Is. But how does this depend on the temperature does it? Come, let us read this also. then this Come and read the small topics later I will take it. But temperature resistivity How does it affect? Let's talk about this too Let's do it. Ok? here we are The study of temperature is for conductors I will read it for you. Bus for conductors only. For Conductors. We only need to study temperature This has to be done for the conductors. Insulators Pay So age really doesn't make any difference. And We have our last chance for semiconductors The chapter is Semiconductor and Electronic The devices will read it there. of butt temperature What does this have to do with resistivity? Come Understood. The change which is in resistance is directly There is proportional change in temperature. I have studied in 10th class. if you If you increase the temperature, the resistance will increase. The more you increase the temperature, the greater the resistance It will increase that much. Talking about conductors I am saying it again. as much as The more you increase the temperature, the greater will be the resistance Will increase. So, delta R is directly is proportional to delta T. Isn't it? End also delta R which is directly Our original is proportional What was before the Resistance. That is, the one which Resistance is directly proportional There is a change in temperature. and the one who changes in There is resistance on this too how much it will change depends if you already have What was the resistance? as much as before The more the resistance, the more it will increase because the greater the resistance There is that much friction. that much More heat is generated. that much temperature Other factors change in. that much There is a lot of change in resistance also. So Delta R is proportional to Delta T and R Both. R is original resistance. So if I If I combine both of these, then Delta R is proportional to what will happen? Delta TR1 now with proportional sign removed If I put a constant here, The constant here is alpha. Now I make the symbols of both almost the same, so You should understand that this was proportional and this was alpha Is. So alpha delta T R1 looking at this one You will remember the formula. Replacing Delta R What can I write? Delta R means Change in resistance which is R2 – R1. So what came from here? alpha how much is this Went? T2 - T1 how much did you bring here? R1 now From here if I write R2 - R1 and this R1 alpha T2 - T1 means at T1 temperature The resistance was R1 and on T2 is R2. This Take it here. So the new resistance is That will become R1 + R1 alpha T2 - T1 this Derivation If you don't feel that Friend, we have never seen it, so it is absolutely correct Because NCERT has a direct formula If it is written then it can be a derivation It may not be in your syllabus or in your exam Even if it is not done in your school but we are safe Let's take it aside and look at this derivation You might also be missing thermal expansion 11th class. So from here we have to find R2 Is. Now what will happen to R2? From here R1 is common Take. So if you take r1 common then 1 + alpha T2 - T1 Now you will definitely get thermal scanning from here You might be remembering the expansion formula. So The new resistance we have is The old resistance will be turned into 1 + alpha T2 - T1 where alpha is one It is obvious that there is a constant which is present in every It is different for one material. But sir There is a heading above called resistivity of. You have removed the resistance. Oho So what happened? Can I use L instead of R/ Can I keep A? then R2 will become RO2 L / A and this will become Ro1 L / A and it will come here 1 + alpha T2 - T1 now from here L / A to L / A will be cancelled. So the new one will cry it will be the old one Ro 1 + alpha T2 - T1 so this is the formula in which Three to four in NCERT There are questions. Many come in the exam too Are. You have to remember this formula and this one Have to remember Phula. On both of these, you You will get questions. You just remember the formula Have to keep it. Derivation I have used in my life till date Never seen this in the last 15-16 years. But who knows, he might come. Derivation Utni It is not as important as this The formula has come down to us. So this one The slide says that the material may vary. Pay resistance will vary. and this one The slide says for conductors Resistivity will increase as temperature increases. Row two will happen at T2 temperature. When at T1 If it was row one, it would increase. Is it okay? so this All things are there. I told you to start Very basic-basic things in half an hour We will collect them. like you're reading something else are the current densities. Then the current density will come A certain angle conductance conductivity. Very basic things. Mainly from here Our studies will start. Mainly studies will start. Is it done? Let us go Come on let's go. On what? a small topic Pay. That is the current density. Now we have normal I have heard about density or mass density. it What is current density? The current density is Current density is how much current flows is on unit area perpendicularly How much current like I have here is a conductor. Ok? and this conductor's If I amount of current is going inside and if its area is A then the current density Which we show with J. of current We represent the current by I and the area by I. from A. So the formula for current density is We'll have I/A done. So the current What is density? How much current The unit is flowing perpendicularly Area? how much current is flowing Unit area perpendicularly? So I/A Will be done. if you read the definition Is this also written in the definition? Can I write q/t instead of current That means charge upon time. so according to that We will also have this formula for it. How much charge is flowing per second Unit area. yes come read it. Current Density at any point inside a conductor is defined as the amount of charge flowing per second Through unit area per second through unit Area held normal to the direction of Flow of charge. What is the condition? which is the area That direction of flow i.e. current where flow It must be happening under his direction. That means the area i.e. the current Perpendicularly cutting it. No If he bites, we will talk about what will happen? Butt if If it is cutting then this will become the formula. Yes. Current density is also a vector quantity. But if it's not cutting perpendicularly Is. Suppose the current is flowing like this. But Our area is situated like this. That means our area is in that direction The area vector that will come in this will come. Now you can see its area vector yes. It is not in the direction of the current. This in the case of will be. I have read the first chapter and it is almost here Its current is also flowing. but if so What if it isn't there? What in between them is angle theta? Absolutely. Now its two I will tear you into pieces, come. we have a piece This will happen, one piece, this will happen. These gonna be A cos theta with theta Going to do. This will become A sin theta. Us Which piece do you want? We need Cos Theta The one. So the current density in this case is, That's going to be I / in A cos theta because We need the one which shows the direction of current I am in it. It was written in the definition. so here From this we will have a new formula. There is no problem. and from here We also got a new formula for current Will go. j a cos theta. Now because j means Both the current density and a are vectors There is quantity. and when along with the vector If we get cross cos theta then we will call it a dot You can also call it a product. So our current Comes close to j vector.Author a vector. like this also You can tell me. Understand? It is a gift. From here Let's talk about its SI unit Are. We could have done that from here also. One That's it. then the SI unit of current would be is the ampere. area is measured in meters Square. So ampere per meter square. very much you can say in a way our It is very useful after going further into 12th. Truth be told, this age will be of no use in 12th. So It's fine for now. Ok. Ok. These small topics quickly Let's settle it. Don't pay much attention to them The more important it is for the future. Come on come. I won't wait much longer like this now On conductance. What is conductance? Conductance is 1 / resistance. The opposite of resistance is called Conductance. So what should I teach in this now? conductance is the result of resistance The opposite happens. what is its SI unit is it bro? What will be its SI unit? Om Inverse. We did this in chemistry Also studied electrochemistry. That's where conductivity comes in. Take it now What to read about conductivity? What is conductivity? Conductivity is 1 / resistivity. Conductivity is 1 / resistivity. Now since the unit of resistivity is ohm meter then its unit will be ohm inverse meter Inverse. I hope if you heard electro If you have studied chemistry then you would know Om Inverse is also called Simon. So its The unit also becomes Simon or its Simon metre inverse. But we are in physics Simon doesn't use it. We are Om I will use it. So its will be OM inverse. Its will come ohm inverse meter inverse. It is the opposite of resistivity Conductivity. Now for conductors, for example Come on, let's talk a little more. Conductors who were conductors There was very little resistivity for them. The resistivity was very low. Low resistivity It was obvious that conductivity was there It will become too much. Did you understand it? Understand What? just like the insulators There were insulators for them The resistivity was very high. The resistivity was very high. lot of obstruction It was too much. So conductivity means electricity The power to conduct was greatly reduced. As the name conductivity suggests, this What is? How easily the current is flowing Is. So it is obvious that it is the opposite will be. These are very basic things. Very basic, Very basic, very basic. start studying in main It happens from here. That is why I will say Revise whatever you have taught once. Because the main part starts from here. Now, we come to the mechanism of Flow of current. call it mechanism of current Flow in a Conductor. In which we have two new we will understand about things and from here some A new life is about to begin. Drift About velocity and relaxation time Will talk. So first the definition of both of these I understand. then derive a formula is the drift velocity which is discussed in this chapter The first formula of is also the first derivation. How did the light go off? Let's go one second. I'll turn on the light here. Yes. So Now if I tell you here that this what is it? What is drift velocity? Come. First let us understand what is drift velocity is it something? Do you guys understand the meaning of drift? You must have heard this name. of drift It means to rub. Isn't it? Drifting to do, to rub. So what does drift velocity mean? What happened? When an electron is placed at a terminal from one terminal to another, then he It doesn't go smoothly. he goes rubbing Yes, we get resistance. Isn't it? then the same We call this velocity drift velocity. Are. so velocity by which Velocity Buy Which Charges Right Now For electron drift. Towards Ojit Terminal. Isn't it? When we use a battery we put it on, if we organize a sale The electron runs towards the positive. And Proton means positive charge, if imagination I make those who don't actually run away run away They will run towards the negative. then how much They will run away from him with great velocity This is called the drift velocity, denoted by v. Let us represent you. and another one as well The thing that is coming is relaxation time. Which we represent as Tau. We represent one more thing with Tau which is torque. but here at We are going to represent from Tau Take care of relaxation time. Now this What is relaxation time? Do your Accordingly, when a charged particle is near a conductor You must be running inside, what if you are running They must contain collagen? they would collide Among themselves. It is obvious. So their two consecutively i.e. of their two successful collisions The time gap which occurs in between we call it It is called relaxation time. so time gap between Two Successive Collisions Two Successive Collisions Off charge particle. Two consecutive charges of a single charge the time between collisions that occur There is a gap, suppose there is an electron which is 8:1 I bumped into it. Now the next one he hit 8:03 you too You know, I also know that there is so much gap Not there. in fractions of seconds that colliding thousands, millions of times Will be. But for now if you believe this So his relaxation time is 2 It's been a minute. because he collided once It is hitting at 8:01 and once again at 8:03. So the relaxation time is 2 minutes Done. So look between the two collisions The electron is going here. been here bumped, bumped here, bumped here, bumped here Collided. So the time between these two collisions There is also relaxation time. also in between Relaxation. So what is between the two collisions It saves time, that's what we call it Relaxation time. now what are we here are you going to do it? drift velocity is a function of We are going to derive the formula. Ok? Come on, let's get started. First comes, Absence Of potential difference. If I am a wire No potential difference applies in would do, if I had a wire, and it had I no potential difference applies I will do it, and he is the conductor, so obviously The thing is, the conductor has free electrons Will be. So here I have a conductor, It has these free electrons. Now this free electrons, because right now there are no There was no potential difference. They have no There is no purpose. So these are running randomly Will be. Must be running here and there. Any He might be going somewhere. Isn't it? because now They don't have any purpose. Nowhere We are going. no potential difference Applied. like water in a bucket It has happened. Someone is going somewhere randomly There is no purpose. take the bucket to a height and leave it. then water will have a purpose from higher potential to lower potential come. There is no purpose here right now. There is no purpose here. So the initial What should be the average velocity of all? Will she go? it will become zero because averagely The electrons are not running away anywhere. So the average What will be the initial velocity? be zero will go. But if I were here to I will apply the potential difference. Presence of potential difference if I here any I will apply the potential difference. So Are all the electrons Where do the electrons go from? Lower They get hired from. Isn't it? positive charge It goes from higher to lower. But if you assume I put a positive here, so Always consider positive as higher potential Are. This is already known. and the negative Lower. so all the electrons Would like to move from lower to higher potential. That means this electron should also go here would like to. Now they have all of these There is a purpose. Now they have a purpose, that this is a Flow in direction. because of which now Their average velocity will now be zero It won't happen. And this is what we call drift velocity. It is said and we have to calculate this. Come Let's calculate this, brother. First We are going to do a derivation. so bro start We do. So brother, v = u + at. Is No? now because u means initial Velocity. So before applying our initial The velocity was zero. After installing it, we I said vd. a is our acceleration and t Our Tau means relaxation time. So The drift velocity becomes a tau. Ok Yes? a tau. Now consider this as the first equation and find the value of a. Newton Geiger's second law states that f = ma. And in our first chapter, we I studied the electric field formula Force/Charge. So we get force from that. Electric field in given charge*. No I understood it. This has arrived. Now we the people Electric field in the first chapter I have read the formula. Force / Charge or Say Test charge. So did the force come here? Pay? Charge in electric field into. Now Because here we are talking about electrons only are going to do it. In our conductor the electron is going to run because Place - placed it. So from here the acceleration The formula has come down to -e e / m The formula for acceleration is given below - /m Accordingly, if I put its value here If I do it then congratulations drift Put the velocity formula in place of a - We already had Tau above. Below our I have come close to it. So congratulations for this chapter The first derivation is drift The formula for velocity is derived - e tau / m is small here e is the charge of the electron 1.6 10 to the power of -19 and greater is e What is the electric field here? relaxation time and m here is the mass of If we look at the electrons then here we are left with everything is constant except electric Field K to Drift Velocity Electric should be directly proportional to the field which should be there because as much as it is You will apply more electric field The charged particle will now travel that fast if if there is electron then against the The electric field will go and the positive charge if it is in the direction then this minus sign This is what Drift Velocity is showing if the electric field is here electric field is here then the electron which The electron always runs here and there moves opposite to the electric field this minus sign here shows this thing which he is doing it, once it's done then it's ours The first relation is over, now we have the second relation Drift velocity is also related to current let's start with the derivation first please with time stamp please I have a request with time stamp Tell me, according to you, when derivation takes place If it goes then the drift velocity and current will be will come in directly proportional or They will come inversely proportional. of thinking Tell. Think and tell me. As long as I'm here I am taking the conductor and in the comment section Write down your answer. whose length I take l and its area of ​​cross section is a I am taking it. Consideration will have to be written. Let Us Take a wire of length l and area of ​​cross If there is section A then consideration will come. Now if it is like that So let's lie down here that whatever n is, it is a number of electrons per unit volume which is called We can also call it electron density. which we can also call electron density how many are there in a meter cube are there electrons? This is called electron density also say or say number of This is the unit volume per electron. I Hope you have written the answer that drift Velocity and current are directly related to each other It should be proportional. Hey brother you are coming If velocity increases then current will increase No. If the velocity increases then the electron The flow will be faster. so this is common It makes sense that the current will increase. ok sir? So a conductor took N number off Unit volume per electron. Now listen. Do we all know the formula for i It is q/t. Correct? q what is it? Total charge. So what will be the total charge? Number How many off electrons are there? into one The charge on the electron which is - Witch is - upon me tau. Understand? Tau means time t. So what did i come here? Now What will be the number of electrons? If I have n number of electrons per unit volume, then the number of electrons will be n into vol. number of electrons will be n*vol. outside we have -e means there is a charge on one electron. This is the total number of electrons. this one The charge on the electron is then this is the total Time to charge upon. Now if this is a If it is a cylinder then what is the volume of the cylinder it occurs? the volume of the cylinder is Length into area. it would have happened brother Is. Now I'm drifting into this formula. I want to bring velocity. Drift Velocity. The goal is drift velocity. So I took the - here. Took n here. a Took him here. took l to the corner and t Took it below. Now l/t means that What is distance/time l/t i.e. What is the distance/time? Oho Distance/time is velocity and Velocity Which velocity are we talking about here Is it happening? So the answer is drift velocity What is being talked about. So congratulations kids yes. We have got the formula for current. The second derivation is done - n vd which is This again shows that the current is drift is directly proportional of velocity which we also had to prove Because e n and a are constants. what is it Is? charge on electrons throughout the universe I will remain constant. n is the number of Unit Volume One on Electrons is a constant for the particular material and a We are not changing. a uniform There is a wire, it is a uniform area wire. a If it becomes constant, then current and drift Velocities are directly proportional to each other It will be done. It should have happened also. also being Were needed. It's done. It's done. be done Went. Now finally what we were waiting for Among the most important derivations of the chapter one of the most important means number one so No, but in the most important derivations Another one of them is Ohm's law. if bhaiya sleep 15 I have been watching the paper for 5-7 years, I am alone You might have found this derivation in the exam 5 At least the year is very important. Ohms We are going to do the derivation of the law. Very There is a small derivation. Very cute and Remember you have to hit three targets with one arrow here. You are going to get targets. Three with one arrow You are going to get targets. First you can read Ohms Law So you will definitely prove it. At the same time as you Here the resistance is related to length and area. They are directly and inversely proportional It happens. You are going to prove this as well. i.e that you will also prove this part that R The formula is roll by A i.e. L and That is the proportional to A. with one Directly with one inversely. and here There is also a new formula of Pay Aap Ro Proof You are going to do it. So, hit three targets with one arrow Will be. But our first objective is Om The law itself will have to be proved. Come on, come on, very This is a small derivation of Ohm's law. What i Formula of -nabd Yes, I proved it today itself. All The formula for drift velocity is - e is tau/m. Put this in it. So the current The formula has arrived -na and put -e in place of vd / m then i equals to minus to minus cancel e² n a e² na tau / m into e aa Went. Got it? e² n tau and e taken out m here. Now because I know Ohm's Law Prove Have to do it. Ohms law means I to Proving V is Directly Proportional Is. So for that there should be a V here But nowhere in this whole formula do I find V is not visible. So I'll open E. Here. So I = E² NA tau / M now In place of electric field I will write V / L I can because we have proven it In the second chapter, the electric field There is a voltage gradient. Potential There is a gradient. Now take everybody over there and Let V be on one side. then m* in l up I went up in e² na tau stayed down And with that we have i come take a look Look, I haven't done anything, I took them all there I have left the v aside now carefully work out this Look at the equation and the definition of Ohm's Law Will you remember that Ohm's Law laid down the first condition that bhaiya was at constant temperature and Listening dimensions carefully at Constant Temperature End Dimensions What about m which is a constant. if If dimensions are constant then l is also constant Is. e² which is always constant. n is constant. a is a constant. and if If temperature is constant then tau is also constant is constant. So is this the whole thing The part becomes constant. If If it has constant temperature and dimension then it The whole part will become constant. And if this entire part becomes constant. So can I V is equals to this a new I can assume a constant R and if this is constant then V because V is the whole R is a complete constant and that means V is Proportional to I became. So congratulations brother ho Ohm's law was proved because this The entire part is constant. when these is constant then V and I are proportional Went. Ohm's law is here, I have to leave it. But let us see what happened now So I proved what the formula for r is Is? m upon e² n tau and with l and is a. Now tell me what I knew Do you think r is proportional to l? Yes. Address Tha a k inversely yes. but before today This was not proved. so prove it here It was also said that R is between L and A is proportional i.e. directly proportional to L/A It is proportional. And you all know that this The whole is a new constant for us which We call it crying. Isn't it? so here We have the formula R = Roll/A. So if we compare it, we also get the benefit of Ro A formula has been found which is M / E² N Tau. So that means brother from one T many We hit the targets. Firstly, we have proved it Given that the resistance is between L and A is proportional and L/A. and here We got Roe's formula. of crying There won't be any numerical above, this is the truth On top of this formula. but yes whenever If Om's law is proof then you can immediately get three You will prove things. you will definitely do Ohm's law will you do it. R is proportional to L and A. These You will also do L/A and Ro's with us The formula will come. Is it done? So this is very There is a more important derivation. Attention Keep. We had space anyway People did a lot of bad work but it doesn't matter no this becomes a derivation You can call this chapter very important This is almost the most important derivation of Ok, please read this quickly and take notes. Let's move ahead brother, let's talk further now So we get the topic, this is it ok so now the topic is mobility of charge Carriers Dekho Mobility Meaning of Mobility What is mobility? The word comes from mobile whatever you want from mobile to mobile its Do the pronunciation, how many How easily is From One moving? Point to another. so mobility of charge What does career mean now? that there is no charge How easily is the particle moving From place to place. Now often here is a Misunderstandings occur. From Let's we have two There are particles. A is a particle and a The particle is B. Ok? listen carefully to this Question. A particle is running, say 100 Meter per second. a charged particle By applying potential difference, electric Divide the field by 100 meters per second Used to be. and the other one is running 200 Meter per second. so tell me quickly comment Who has the mobility between A and B on the section Will it be more? Just write it in the comment Who has more mobility? Is it okay? Quick Write it down from. Ok? so many of you All the kids must have written that bhaiya B's There is more mobility but actually it is like this Not there. Some may have even written that this Depends on how much potential you have Or how much electric field has been installed. Electric Field and Potential Directly Proportional to each other. But how much have you The electric field is given to it so that it moves Do. Now you think, according to you this is 200 rupees If it is running then its mobility is more. But if I also include the electric field here Should I pay if I had said that I had paid 5 here too? Coulomb's electric field applied to Newton And here also it is 5 Newton per Coulomb. So we It can be said that B has more mobility it will happen because it is in the same electric field He is running fast. But if I try to copy this data let me change it and I'll tell you that I have I have applied 10 newton per coulomb and applied it on this is 10,000 newtons per coulomb. So on this After investing 10,000 it ran at 200. So it is obvious that B has a lot of mobility It is very less because if you invest 10 then it will get 100 ran away. This is Rs 200 run on investing Rs 10,000. So who has more mobility? the sharp part What is happening to him? No. No. the sharp part Minimum electric field is being applied On doing it. So what is the definition of mobility? She goes? Drift Velocity Drift Velocity Off charge. Unit on Electric Field Applied Unit electric field applied per unit area How much electric field has been installed? Isn't it? How much electric field per unit Meaning divide by electric field. So What is the drift velocity? Unit on We call this the electric field Mobility. We show mobility From Mu. mobility of electrons also it occurs. Mobility Hum Semiconductor Chapter I will study. It also has holes. As Electrons run in our conductor Are. We will study it in semiconductor there Holes also run along with the electrons Are. For now if I talk about this mobility If I come to the formula then it is the formula of mobility What should we get? of mobility I should get the formula how much velocity is there Which is drift velocity of a particle but how many units i bought it for electric Gave the field. Isn't it? We have understood that. that we Understand. Now if the formula for mobility mu If the mobility formula is mu then We show drift velocity as v and we will denote the electric field by E Let's do a show. So then here we have What is the formula for mobility? Unit Electric at Drift Velocity Field. You will definitely study SI units etc. but Unit Electric at Drift Velocity The field comes to us with a formula. Let go. Now from here if we consider its SI unit Let's talk about it. So the velocity of What is a unit? there are seconds per meter Is. and we have two types of electric fields There are units. one is a volt meter and one is a Coolum is on Newton. You put whatever you want For now I'm here at Coolum on Newton I am applying. ok sir? So this According to this, what will be its unit? Our The pass will come up. Newton's Inverse Will be done. It will become seconds per meter. If If you had used a meter on volts The value would change. Isn't it brother? So if Mobility is high, it means charge The particle easily travels inside a conductor running and if mobility is high then The current will also be high and the next relation will be This is how we give people mobility and We have to find out the relation in electric current. We already know without removing the relation that both are directly connected to each other Should be proportional. If mobility more means less electrons When an electric field is applied more than If the current is running too fast then It will increase automatically. So the current here is More should come. and yet its a small Do the C derivation. very cute little one C is the derivation. We all know that I Formula of - say ENA vd or say ENA vd Take. You have nothing to do with direction right now Is. What does the minus sign represent? that drift velocity and current opposition For electrons in direction. Ok? Also, what has come to us today that the mobility of The electron is what drifts The unit electric field per velocity is Is. This is mobility mu. So from here What is the formula for drift velocity? Will you go? Moving Mobility Into Electric Field. Correct? Now it drifts to us The formula for velocity has arrived. this in this Put it in. Consider this as your first choice. This Assume seconds. Putting Second in first. Now if I change the seconds I will put it in first. so i have Relation between current and drift mobility Will go. So I had the formula for current -no. Now what have I put in place of vd? Electric Field in Mobility Into. So - Nee Take it apart and take mobility apart. Now for a conductor all these are constants for a given Potential Source. So this means the current that is the drift velocity directly It is proportional. I told you to Small topics will come. These All the topics have some marks somewhere Indirect question in number two and number three Questions are asked about this. such as limitations What are the limitations of Ohm's Law? What is the limitation of Ohm's law? and let's see So we're going to study ohmic and non-ohmic Substances. Isn't it? It is very easy. Short Let's talk to you. Ohmic conductors or What are substances? Such substances Which Follows Ohms Law. which follows Ohm's law. Meaning those whose So if you plot the V and I graphs, then it will Let there be a straight line like the one we made today Because V and I are proportional to each other Needed As an example, you can say Metals. For metals if you use V and I will you make a graph or will you make I and V graph like You can talk as you wish. so that is a straight line It should come and it does come for them. So ohmic Substances are those substances that give Do you follow? Follows Ohm's law. Isn't it? And are there any such substances as this Those in the world who do not follow Ohm's Law Are? Absolutely. They are named non Ohmic Substances. Now it becomes obvious that non ohmic substances are now our It is not in the syllabus. Right now the syllabus means this Of the chapter. But you will say semiconductor Sir, you have mentioned so many things in this chapter. These are semiconductor dialects. which day I have studied semiconductors. Lots of kids There will be droppers here who will watch this lecture There must have been other semiconductors somewhere He has read it. They all know I'm right I am telling you. that semiconductors are our conductors They are very different from. His studies It is very different. So semiconductors are There are examples of those who do not follow Ohms Law Which do not follow Ohm's Law. Those who do not follow Ohm's Law Are. does not follow Ohms law anymore This means that V and I are proportional to each other. Does not happen. I am more of an example of this I will not give any example because I Let me give it to you. You don't understand it yet will come. But PN junction PN junction The most important topic of semiconductors There is one. I just want to make a graph. This graph How was it? You won't understand this right now. But suppose you know that its The graph is something like this. How? It happens? From here it goes like this and from here It goes like this. Suppose now you know that This graph is like this. So is there a V here? and I are proportional to each other? is here The graph is such that Bhaiya V will increase Then I will increase. That too will increase at an equal rate. R will it be constant? No. here you see This is a very strange graph. Different In quadrants. All of that means to us now I don’t want to know. We have to go to semiconductors In. All you need to know is that there are two There are two types of substances: ohmic and non-ohmic Omake. Those who follow Ohm's Law. If I apply voltage to them then current will come Will increase. If I apply voltage then current Will increase. But there are also non-ohmics in the world. In which if you pass current then you Voltage and current are directly related to each other It is not proportional. ok sir? Read it quickly. Superconductivity. We what did you just say that if you are a conductor You will increase the temperature inside. if you If you increase the temperature inside the conductors Resistance will increase. You talked to me, right? So if I reverse it if I turn the temperature down So the resistance will also reduce. so one A level where I can tolerate any substance I will cool it down so much that its resistance will be almost If it becomes almost zero, we will call it that Super conductor. Look brother what is it? The Phenomena of complete loss of resistivity i.e. resistivity approximately equals What should happen to you? It should become zero. See Exactly zero so do it practically It is not possibile. Theoretically you can do it. But if the resistance increases with the increase of temperature and As resistivity increases, the temperature decreases If it happens, both of these will also be less. Now if less then you must understand that if The resistance started decreasing, resistivity If it starts decreasing then the conductivity will increase. and if its resistivity and conductivity When it becomes almost zero, it becomes a superconductor Will go. Isn't it? and the temperature at which this happens he might have a critical temperature or else Also called transition temperature. Which is 100 books will say look you just accept one MCQ came and said critical Any conductor will lose power when the temperature goes down What is the resistance of? Option I will be zero. then we will mark zero We. But you should know it practically It should not be exactly zero is approximately equal to 0. So What did we name that temperature? Is? Critical Temperature. now here's another one Chota, look friend, don't face all these in exams The chances of something coming are almost zero. Correct Isn't it, son? I am not saying the board The paper is saying go and check it. Because If anybody is making board papers So this is the least important thing in his mind Things move on. Meaning if I send them a PPT I don't bring it in writing, to be very Honest. I might forget to teach you go. Because it is not that important. Do you know the most important thing in this chapter? What is? The one on whom the question is bound to come This is it. This is it. We are waiting for this. You should understand that questions are bound to come from this. The meaning has come to you, understand the meaning. understand the meaning It is in your paper. Is it okay? Come on come. But What is the Messner effect so far? Value Let's take this, I have a conductor. And The temperature of this conductor is critical Temperature. We call the critical temperature T Let us show it with C below. So Critical If its temperature is higher than the temperature So right now this is a normal conductor. right now this is super There is no conductor. So for now this is the one is a normal conductor. But if I did this lowering the temperature below the critical temperature If given this, he will become a super conductor. it Will become a super conductor. Yes and no. Yes. Now if I introduce the electric field inside it I will get it passed. If I am inside this I'm sorry if I'm inside it I make it pass through the magnetic field. Not Electric field. If I am inside this If I pass a magnetic field Brother, the magnetic field is of a hollow conductor It can enter from inside. The magnetic field is The hollow can pass through the conductor. So If I measure the magnetic field around it If I apply a magnetic field She will behave normally. because this is normal now is a conductor. If I measure the magnetic field a hollow conductor electric field hollow conductor Can't go inside. but magnetic The field can go. But Masnar ji What did you observe? They observed that if I have a super conductor and that From inside the super conductor I am around him If I pass a magnetic field through Am. then the magnetic field is near it And she goes away. to be inside of it instead. And this effect is called MISCERS Effect. What is the Mizer Effect? If I magnetic field passes through a conductor If I get it done then she will get over it. But If I am a superconductor, i.e., such a body whose temperature is higher than the critical temperature It is less. If I can use magnetic force from inside it If I pass the field then it will pass through it I walked around him instead of leaving will go. Bernoulli's theorem-like diagram You may be seeing 11th class here. So This is the muscle effect. again as much It is not important. Is it okay? But From here we are going to start such a fuzz due to which most of the things in exam are will come and we have done all these things in series and parallel I have studied heating effect power in 10th but You will get all this by going ahead and reading Kitchoff Law or Cell Helping you read in series and parallel do. Is it okay? come on series parallel We do. then after that a couple of Let's see the demonstrations. then heating We will work on the effects. Come on come. I think Everyone remembers this. If you don't remember, come and remember Let's assume that if we have some resistance Some resistors are connected in series such as this we have R1 R2 R3 this we have series I am engaged in. So the current value in the series is same It happens. And the voltage varies. These We also read in the second chapter capacitance It has happened. Now, if current flows from here then Whatever is the current across everyone will come. But if the voltage across it is V1, Across it is V2, across it is V3, then The total voltage we would have applied would be like this There might have been some division. That means, what we The total voltage applied will be equal to V1 will be equal to V2 and V3 because It is the voltage that is divided. In the series The current remains the same. Now the voltage We have the formula I R net. These It's done. R1. This is done. R2. This is done. IR3. Why did I take I beans? Because Series The current remains the same. I will take the common one. i If you take the common one it will get cancelled. you know Hey friend you know what's going to happen. Is No? I didn't even put in much effort on this one remained. I think some of you The kids might have skipped it also. and if If I might have skipped it, I don't even know It would be that I am saying these things You have skipped it. What is deep? The The point is, son, that the resistance we have It comes in series R1 + R2 + R3. I hope you all expected this. This formula is in capacitor in parallel had come. Do you remember? Remember Thumbs Up? Do you remember? Do you remember? Come on come. But here, if our Some resistors are installed in parallel Are. What are the identification of parallel combination it occurs? Identifying Parallel Combinations it happens brother in parallel combination The voltage remains the same but the current Whatever there is, gets divided. Assume here I current is coming from. so went away from here I1. I2 came from here and I2 came from here I3. This is what I have R1. I have this R2 is done and this gives me R3. But the most interesting thing is that these The voltage across them is VV which remains the same It is of this. Isn't it brother? so now if I here From this I net current has been passed into it I net So I net current is basically I1 + I2 + I3 It will be equal. Isn't it? it is an obvious thing The current might have come from here. so those are the three parts It might have been divided. charge can neither be Created nor be destroyed. So that's theirs Sum I will be equal to net. now ohms law According to this, the formula of I is V / r net Is. here comes V / r1 V / R2 and V / R3 Why am I taking V beans? Because the voltage which It remains the same in parallel combination. So it becomes 1 / R1 + 1 / R2 + 1 / R3. From V V got cancelled. So 1/R net is 1 / R1 + 1 / R2 + 1 / R3 so on as many Yes, we had expected this. Me Looks like they skipped this part That's good because I've read this before and this was the result we knew. But Can its derivation come in the paper? Chances are 1% out of 100. Numerical Will come. We are doing V Stone in it It will be useful. But yes, its okay. ok this It is definitely something useful somewhere. Now Let's understand how our A series We call combination and parallel combination You can understand how the current is being divided no it's not happening. like if it passes This is a parallel combination. Parallel Combination We use the same in our homes as well. Isn't it? If in parallel combination any one If I turn it off then current will flow to everything else will remain. And this is the reason why parallel Combinations we use at home Because if I turn it off or this If it gets damaged then the current is here and here It will definitely go. Isn't it? but series combination I can't do that. If someone in the series also due to being late i spoilt it or this If the circuit is turned off then the entire circuit It will become incomplete and current flow will stop Will be done. So if one runs in the series then all the Will go. If one closes, all will close. But this does not happen in parallel. Plus in series because the net resistance If the reciprocal is equal to then the net resistance It decreases. but in parallel sorry Sorry my bad. Net in Series Combination If resistance is added then net resistance It gets quite high. but right there Net resistance within parallel combination It is very low. as an example We have 2 ohm + 2 ohm + 2 ohm in series So it is 6 ohm. but there it is If they were installed parallel then 1 / 2 1 / 2 1 / 2 1 / r comes. So this comes to 3/2 1 / r. so the reverse On doing this R comes to 3/2 which is 1.5 then you see Can you imagine how much difference there is? it is because The resistance in parallel is quite More decreases and this is also a reason that At home we use it in parallel To. But the biggest reason is that parallel The voltage is same in the combination. So Every appliance in the house should have the same voltage It is available. So it works better on the same voltage do. If suppose someone has low voltage If needed, it will reduce automatically. But we all Will deliver same voltage. In the Butt Series Everyone gets different voltages. So Fluctuation occurs or may occur. So There are many reasons why we stay at home Which circuit is used in parallel? And let's take a quick look at these things will rise again. so this is the series we have It is a combination. Now in series combination You probably won't understand if you see it. But this is a series combination. Three Bulbs It might take some time. It is switched off now and I am going to replace all three bulbs with 100-watt bulbs. Are. Keep this in mind. and the three bulbs If I put them here one by one then Right now it is off. But if I If I turn on the switch from above what will you do? will we get to see it? Look at this. what is 100 watts if the bulbs light up like this then the answer is absolutely Not even. are burning very little and if I If I remove one, the rest will also be closed have been. So there are two things that you need to observe It is necessary. First look, I can buy any bulb I am taking them out and the rest are closing down. Because any device in the series Cannot be turned on or off individually. and overall The brightness of 100 W is too low. Now I will show you the actual brightness. But if I remove these three bulbs And after removing this, now I have this parallel Should I take the combination? Maybe you can see it. it All three wires are connected in parallel Are. Even if you can't see it, it's on me Believe me this is parallel to all three All three holders are connected. Now if I I plug it into my socket and the same thing happens The bulbs we just lit in series. See I have kept those below. those same beans If I put the bulb in it and if When I switch it on, observe carefully what That would be a 100 watt bulb actually You have to see at what power it burns. And as soon as I turn it on. so you Look, actually the camera has set its brightness Reduced it. This is a defect in the camera. Initially you remember, just look at this immediately How much more than? This is a camera defect who is dimming his lights. But Actually 100 watt bulbs are so much Burns with brightness. Now if I were to I'll take one out too so you can see The rest are also burning. Why are you burning? Because this is a parallel combination. Any Should I take one out and put any other one in it? It won't make any difference to the rest. Because in parallel combination we call things Can be switched on and off individually. And their The resistance is also low due to which the current is also It is too much. okay brother? series parallel bit It became a bit clear. Now let's talk about heating Effect of current. You guys should also study this in 10th You have done it. So the heating effect of current is According to this, actually whenever we see the conductor If we pass current from inside then we get three The effects can be seen. There happens to be one Magnetic effect on which the next chapter It is ours completely. One is a chemical effect in which in electrochemistry we People study chemical effects. If you have If you have read the electro chemistry chapter You will know that in electrochemistry We are studying how chemicals Energy to electric or electric to Convert to chemical. But when we passes electricity through a conductor So another effect is seen, that is Heating effect. So what whenever a If current passes through the conductor then heating will occur You will get the effect. The answer is yes, you will get 101% I will get it only. The only difference is that sometimes Sometimes you get too much and sometimes you get too much get low. When did the weight ever get so heavy that you use heat in that heating effect Do you. And sometimes the load is so less that you I can't even feel it. such as I have There is a wire here. this wire is of the mike Meaning the wire goes through my body It is also happening. Now it is so here There must be current flowing, right? but it is so little that I can't even feel it. but right there Inside the pay iron, inside the toaster Well, microwave is a very different example Went. The way to heat water is done, geyser Done. These have such a high heating effect that we see, that we feel and that we We use it as well. So Jul ji said the most First if you talk about Joules law of heating The heating effect produced according to Is. The heating effect is produced We know this. but according to Joules Law of Heating Heat produced How much heat will be produced is the most The first thing is directly proportional to the current will be the square of. We can also prove this law will do it today. But whatever this heating effect It is generated as a function of the square of the current Is. It happens due to electric current, this is common sense. Because the current itself is creating the heating effect Is. So if the current increases then the heating effect will increase It will be more. How did Butt Square Pay come about? These We will drive. He told that The heating effect is also present in the resistance It is directly proportional. Should be. How is the heating effect produced? you are such you can understand that when from inside the conductor When electrons travel, they go into the wire Let's rub it. I rub and I rub. Now he if you rub it then it is obvious what that is Will you produce it? Heat. So the more obstruction the more the friction will be You will also get more heat. and last but not the Least heating effect directly It will also be proportional to how much you have Current has been passed through it for a while. Now if I add all of these up Combining Firsts Second and third. If I add these three together If I give it then the heating effect is this will be proportional to I² RT. Heating The effect will become proportional. Of RT. Now according to this, if I take the proportional If I remove the sign of and apply equals then I need to put a constant here. And we're calling that constant k here. Are. Here the value of k is approximately Forest Eye. The value of k is not always the same, right? Something or the other will come. So here the value of k Approximately one eye. in accordance with which We have the formula for heating effect gone i² rt. We will now know a little about its formula going to drive soon with these 5 Two 10 minutes. But yes, what Jul ji said gave the formula, Joules law of heating which Gave the formula, it came out to be I² RT. As much The more the current, the more the heating There will be an effect. Actually Square, Current Double If you do this, the heating effect will quadruple. Will go. You will triple the current and increase the heating effect It will increase nine times. Directly There is also proportional to resistance and It is also directly proportional to time. Understand this much. Now the heating effect would have been created Is. Whenever heat from within a conductor If current passes through the conductor then heating will occur The effect will be created. But what of its Are there any disadvantages or advantages? so obviously The thing is, it has some benefits too. loss then It is there. I don't want heat everywhere. As Right now my top is up here and some lights are on Have been. There are lights here and there, so these are in the lights I don't want any heat to be generated. I am so I would like there to be light here. Why should I I would like there to be heat generated here. like right now We lit the bulbs. why am I in the bulb I would like to generate heat. I would like it to light. So there is heat loss there. But the clothes If you want to iron then you would want to generate heat yes. You need to heat water and make toast So you would want heat to be generated. so over there So you want heat to be generated. so obviously That's right, we will also read about its benefits. But Before that we have to read a topic in between There will be electric power. Power means you all Let us know the rate of doing work. So Electric power will become the rate of doing Electric work. Isn't it brother? So The Edge in Electric Power and Power is Really Something There is no difference. We can do any work only with power They are doing it. In electric power, we People are doing electrical work. They are doing electric work. and work And energy is the same thing for us. So say unit time on electric work or electric energy per unit time Take. So the power formula is work done In our time even a KG kid knows this Is. According to this, what is its SI unit? Will she go? Isn't it? Isn't it? Isn't it? Everybody knows it Dude Jul per second. And it has another unit, that is What? Named after James Watt. He made a steam engine which was very He was powerful. So, it got this name. Such a unit. When will 1 watt arrive? hey when will 1 watt come? 1 Watt will come when your device consumes 1 joule every 1 second Either it is consuming energy or say It is doing 1 joule of work. The matter is the same. So we will call it electric power. In practical life, the more energy you You consume it in different forms Do you do his work? like a tube light Is. Let's say she's eating 40 joules. Absorb Still working. So out of that she is giving light worth 30 It will be there but it is also giving heat or sound of 10 It will be. So the more energy you eat, the more work you do So you will do it but how much of your useful work is this In practical life it would be very different Is. Are you able to understand? We who have just We saw bulbs that we want to use at home Why did you stop it? because that energy Used to eat a lot. In return, it gives us energy He used to give it also. but a lot of energy from it There was a sound and the bulb was heated with sound energy It is not made for. You all know it, right? So that's why we stopped using it Gave. Now we use LEDs here Are. Can be used in your homes as well Will be. Isn't it brother? Let us go. now what do we have Are there other formulas of power? Absolutely. How did other power formulas come about? What We have the power formula, work done upon Is it time? Absolutely. do i work Write the charge in potential into instead of done Can I? Absolutely. because this chapter The first formula of the second chapter was Potential is work done upon charge. So Instead of work done, I wrote potential Charge into. I charge accordingly What can I write to Upon Time? Charge Upon time I can write current. So I have come up with another formula for power. which is voltage into current or Current into potential difference. so one We had this formula. one more come Went. well also do we have the power Formula If v * I is arrived at then replace v with I can write IR according to Ohm's law and There was already an I so the power formula It has come to me i²r here you go here one more formula aa gaya and also Power formula i has v * i of i again v/r from Ohms law instead then v * v will become v² If it becomes v² / r then mark it in red color What all formulas of power do you use? It's done, work is done / time is done Current into voltage. current became one Square into resistance and be one The square of the voltage given is Resistance. All formulas in themselves It is important. hey this red and white together It looks orange to you. Isn't it? Let's go. But the point is that we have three or four of these Formulas of power are available. Is it done? 1 2 3 4 ok? Ok? Ok? then power a What is? rate of doing work is called Power. I have studied all this in 10th. Yes, I am completely educated. so a little faster I read it. Now on Commercial Unit of Energy coming. Look at this much commercial we will do it in units and in this much part we will Joules proves the law of heating Come on. Ok? Proof Off heating effect = I² RT come. Me I don't think this derivation ever appeared on the board will come. Son, there is a lot of good in this chapter is about to come. But let's do it nonetheless. Come on. Should it be said that the power formula is i²r. Proofed it today itself. Here it is. Correct Is? Blessed. So Another formula for power is energy/time. If you equate these two then i will Energy/Time Equals What Will Come? If you take i² r time there then the energy Has the formula arrived? Take i² rt. Now if you If you are producing a heating effect All the energy is in the heating effect It will be converted. Because you believe that that the energy you are producing That is happening only due to heating effect. Is No? You are assuming so. So, according to this, our The formula for the heating effect is I² RT Will go. Commercial Unit of Electric Energy. Ask a question before reading this I would like to meet you all. It is a question of honesty. Ok? Tell us in the comment section. Time Check the stamp. If I ask you that How many joules can you generate in your home in 1 day? Do you spend energy? Answer quickly. How will you convey the meaning? Give it like this. In thousands, In lakhs, in crores, in trillions. As such If I ask you that in your house you 1 How many joules in every second within a second Do you expend energy? So what about this Do you have the answer? Tell us in the comment section. I gave it. In thousands, in lakhs, in crores, In trillions, how many? Ok? Let's go here now Some of you have given some answers. Something or the other. but to give you an idea I would like to If our AC is of 2 ton like this There is an AC installed in the room which is of 2 ton Is. It is of 2000 watts. Let's accept it. 2000 1 watt AC generates 72 lakh joules in 1 hour spends energy. How? of energy The formula is time into power. I told you its power is approximately 2000 It is watt. Because it weighs approximately 2 tons. Time How much do we have? 1 hour. in 1 hour How much time does it take? 3600 seconds. So After multiplying it, we get 72 lakh Joules. i.e that this AC which is installed in this room 72 lakhs every second every hour That's all Joule spends. so imagine Do it in my house or your house Appliances together consume trillions of joules in a day Let’s do it very gently. like this one shot If it took me 4 hours to record Because there are cuts in the middle also. Then There are also experiments. so 4 hours It is going on. Now you add four more into it. So this answer has reached crores, right? The only point is in our homes when we If you use energy then a very big number It happens. That's why we built another unit at home In order to measure the energy which we have Said Commercial Unit of Energy and The commercial unit of energy is kilowatt R. A lot of kids make mistakes here. are in writing kW R. kW R It is smaller than a kilo. Watt w big and h is small in R. And Because it contains a lot of watts As soon as children read kilowatt r they feel that Whose unit is this? This is a unit of power. But actually this is not a unit of power Is. Whose unit is this? It is about energy. Is No brother? 1 kilo watt r. this is called Kilo Watt R. Now whose kilowatt R is this Is it equal to? So 1 kilo watt R would be This is equal to 36 lakh joules. That is, if you spend 36 lakh joules of energy yes. If you spend 36 lakh joules of energy You give it and then you get 1 kilowatt Hour which is also called 1 unit and our The electricity charges that are made at home 1 Kilowatt is taken from AAV. 1 kg now 36 in watt R i.e. if you assume your area I am saying that one unit costs ₹5 So this is what unit means. i.e. when you are 5 If you spend one kilo watt then you will get Rs. 25 Will take. If one unit is for ₹5, then do you understand? If one unit is for ₹5 then if you spent ₹36 Spent a lot of energy. ₹36 lakh means 1 For kilowatt R you have to pay ₹5. all day long Let's say if you spent 20 units then If 20 kWh is spent then 20 * will cost ₹36 5 in lakh and 20 * means your It became ₹100 per day. some account like that It's done rough. Now where did this come from? so this Where did it come from? Let's take a look quickly. So 1 kilowatt R means 1 Kilo watt* in 1 hour. Isn't it brother? 1 kg Watt means 1000 watts. 1 hour It means 3600 seconds. Now, because 1 watt is 1 joule by 1 second which is 1000 watt will take 1000 joules up in 1 second into will be cancelled from 3600 seconds so here we have 36 1 2 1 2 3 Joule will come i.e. in 1 kilo watt R How many joules are there? It becomes 36 lakh joules. 1 How many joules are there in a kilowatt? 36 It's a million Jules. So 1 kWh R costs You spent 36 lakh joules to do this. Its This is what it means. Done. Let's close the application now Again very high on heating effect I will not make any effort because I am in 10th class Is. But son, some indirect question may come Is. The first advantage is the heating effect Electric fuse. Isn't it? Now again, have we bought an electric scooter? The fuse has stopped being used At home? It has reduced a lot. Almost none. Now We have manual circuit breakers i.e. that the MCBs have arrived. whose principal The way of working is very different. Butt Fashioned What used to happen in it? The Men in Our Homes There was a line which brought electricity from the main line She was one before she entered our house It used to pass through the safety device which We used to call it fuse. It is made of copper wire Hui wire: This is a wire made of copper It was made of copper. Now this would have been the fuse Its length, breadth and thickness were as follows It was kept that if there was a certain amount in it If the current was more than the off current then heating It would melt and break due to the impact. As an example, assume that I said That this fuse is a 15 ampere fuse. So If I am talking about this fuse being 15 ampere If the fuse is of , it means that if More than 15 amperes of current is passing through it It passed. Current pass more than 15 amperes If this happens, it will melt due to the heating effect. It will happen and if it melts, it will break And if it breaks then it will break the circuit and that Much current will not be able to enter our house. Because neither before nor now there is much work like this It happens. But earlier electricity used to be government owned It was on a large scale. still some states In some places it may be government yes. But where I live in Delhi this He is Tata i.e. Ratan Tata ji, the full name of Tata has become private in a way. so now fluctuations do not occur because things Things have gotten better. It has become better. Service It has become very good. So now fluctuations There aren't that many. But there used to be a lot of them earlier when I was in 8th or 11th or even younger. Was. At that time electricity used to be government property. then between I became semi private. Now it's private Went. Here in our area your area I don't know right now. so what would have happened Is? Suppose if 17 ampere 20 ampere current When he came fluctuating from behind he was very There is high current and if it enters our house If I went, then out of all the devices, some devices It can get damaged as it runs on 20 amperes Not made for working. So this fuse What was he used to doing? At current above 15 amperes produced so much heating effect that it melted and the circuit and then switched on the house lights She would go away. Then we used to take it out. One put in a new fuse wire and then Because that would happen for a very short time. But it was a very time consuming task so now This is not used. comes again We have electric bulbs. again use electric bulbs too We have closed it down. even if your house is still You can buy an electric bulb and install it If you are doing this then I am sorry but you are being stupid. There is an old store room somewhere It is a different matter in other things. or someone else You are doing photography with a purpose. some more If you are buying bulb for some purpose then it is different The thing is. Now what is the harm in the bulb? because it generates a lot of heat There was a lot of energy loss. now good Technology has arrived. But these were bulbs. These There is glass covering, you must know and this Inside the glass covering, we inserted Gases such as nitrogen, argon, neon As it was filled with inert gases. Inert Gases because there was a metal inside it. The name of the metal was tungsten. and this tungsten Metal which used to be very high melting It used to be of points. High melting point. has a very high melting point Was. Very high melting point 1300 that despite it being so thin, It used to be so hot too. used to glow Because of heating effect. But in this It did not melt. and oxygen to prevent fire so that it does not react, keep this one around Used to fill gases. So if I go without this covering What will happen if I light the bulb? You You may have seen it in many places, I would show it even today Am. But it catches fire due to tension It reacts with oxygen. But If we come on the last application then heating Appliances. Now as many as heating appliances We also have devices like geyser It's done, the toaster is done. Isn't it? in heating We use an alloy in the devices Are. And the name of that alloy is nichrome. Actually in nichrome alloy we have It is mixed with Nick plus Chromium Na and Nickel and Chromium when mixed together Their resistance is very high It happens. Reasons for high resistance This also increases the heating effect. So in heating appliances, heaters etc. we Nichrome is used. I'll give you nichrome Let me show you something on top of that as well. see quickly Are. Then we will come to the main thing which we need Wait that is the crux of the law. but come on Take a quick look at the heating and devices first And look at the electric bulb and then move ahead Are. So now we have this bulb which We have removed the upper covering. Now If its covering has been removed Once you turn it on in slow motion camera, Let's do it and see what happens. Let's go then You will see as soon as I switch it on. Look, it burned for a little while, but due to it being too hot There was oxygen nearby. reacts with oxygen Went. On reacting with oxygen it Created tungsten oxide. touched again Look, and it's burnt basically. So this is my nearby you can see there is copper wire and Below is nichrome wire along with copper wire. Now because from here I have this copper wire It is coming. Next is Nikonchrome If it is copper then it means it is sure that both are connected in series combination Are. Now I can plug both of these in the socket of my house by putting it in, if current passes inside it If I get it done then the current will be the same in both We understand this. Because the combination series but because of the nickelchrome The resistance is very high. So this is us expecting it to glow a Turn. So I had to change my location a little bit. Had to do it. But I put this socket here The wire has been fixed inside the socket. Now if I turn this on you will notice One thing we need to see is what is that? so like hey i can give this to you one second please Children, do not try this at home. These That will be my request. So as soon as I turn it on, it's on are done. How do I know because I Vibration is felt. too much There is current. So maybe you can see that I held the copper wire in my hand It happened and I have nothing. but this The wire has turned completely red, if you If you can see it. So what is actually happening Is? The current is same in both. Now the current is same in both. but what so It seems that this one is getting so hot It's gone, it's glowing. So what will happen? One I often turn it off because Keeping it on for a long time can be a little dangerous because the room I'm in The room is actually filled with Styroform Is. Now will the current be the same in both the wires? was because copper wire and nichrome wire Both were in the series. but of nichrome The resistance of nichrome is very Is greater. because of which we get heating The effect was greater. so it's not hot It happened but the road below became very hot. So this is actually the heating effect of current I shows that if the resistance increases then The heating effect will also increase. okay brother? so i hope till now you have The concepts have been covered well. Now let's talk about question answers. So, we will ask some questions. Some MCQs and some are subjective as of now Of the topic. then read further topics Are. Right now a very important topic i.e. Crutch Of law is left. then Wheat Stone Bridge then the cell series parallel internal resistance The one with the cell. very important topic There are others left ahead. Majorly the questions come from there are going to. But even from here the question still remains I have read it, it comes from that also. come one turn Let's make answers for these. Is it ok brother? Now You will have two ways to create answers. The first way would be to pause the video Do that and make them and then match them. Or So you can make it together also. Your choice Is. Ok? Come on come. such as the first This question is coming to us. what are you saying do you have a question brother? The Resistance is asking questions of a wire of length is a wire whose length You need 100 cm. I have given it. now 100 Cm. I don't like it. So I to this I will convert it into meters. end of Uniform area of ​​cross section area of The cross section also gives you 0.02 cm² It has been kept. Again, I don't like this either. So To convert this into square meters So, I'll raise 10 to the power of -4. So the total Mixed 2 * 10 to the power -6 m² area Will go. It is done. And the resistance you get from it I have got it and I have given it to you 2 ohm. As yet By looking at the data you must have understood that bhaiya Which formula should be used? beacuse you Specific Resistance Specific Resistance means resistivity. Specific resistance means Resistivity. That means you have to cry Is. So by now you have understood the formula brother who is it like? which formula is it bro? Then, R = R L / A we get the formula. Is it done? Now we have two R i.e. resistance. We have to calculate Rho i.e. resistivity Have to do it. L is the length that we have That is 1 meter and A means the area which we have The nearest thing is 2* to the power of 10 - 6. The calculation is also very easy. it looks like that This is a question of 10th class. butt exam The PY that comes in is Q. So 2 * 2 4 * I remembered the 10^-6 SI unit It will be. The answer will appear in the ohm meter. Oho There are good questions too. This is just the beginning No, that's it. Yes, it is a beginning. But this means that It is not that you underestimate such questions will you do it. Such questions are also equal in your exam This is very important. can come in single number Are. It may come in MCQs. any big It doesn't matter. It's fine now? Come on let's move on Are. Again another question in All India 2025 has come. Let's understand what it is saying Question. Two wires of the same material. Beans If there is material then it means both There is resistivity, it will be the same and the same Radius means if the radius is same then it means both The area of ​​the cross section will be that will also be the same having their length in the ratio but if the length of one is 2x then The length of the second one will become 3x ours Because the length ratio is 2:3. They are connected in parallel. Ok? to a Battery which supply current of this battery total I will explain the current with a diagram now To you. The total current it is giving is 15 amperes. Find the current through the wires. tell you How much current is there in both the wires It will be divided. Look, it is certain that if one the length of one is 2x and the length of another is 3x and we Everybody knows that the resistance is It is directly proportional to length. Balance If everything is equal then directly proportional to the length It became proportional. So whatever the length The ratio will be the ratio of resistance. I hope you know. It means that which Resistance is first and resistance is second If its length ratio is 2:3 then Their resistance ratio will also be 2:3. The ratio of its resistance is also We will get 2:3. but what of will it prove? Come let us understand this. Now if a Look at the length of there is a resistance whose The length is 2x and there is a resistance of the length we have 3x and these two are what did we do with each other in parallel Already done? is connected and After connecting there is a cell battery Whatever it is, I have put it up. Is it okay? Who I have installed it and turned the switch We are on. ok sir. Now they are saying that the total current coming out from here which The total current coming out from here is 15 The ampere is running out. The total current from here The current coming out here is 15 amperes. Now if their resistance is 2:3 if their If the resistance is 2:3 then the resistance and current They are inversely proportional to each other. If it is connected in parallel, you will Have to tell the current through the wires total 15 The ampere has come out. and the resistance ratio If it's 2:3, I hope you know that too that the current is inversely proportional to the resistance It is proportional. Hey hey hey Ohms Law. And if it is inverse then it is not Ohm's law But it came from Ohm's Law. Now if this is inversely proportional then R1 / R2 It will be the opposite. So the current which is I1/I2, That will be R2 / R1. R2 / R1 will be reversed. which means I1 / The ratio of I2 will become 3:2. They It will become 3:2. So much of this is physics. Now what I'm going to do next is maths. Our physics has become so advanced that brother, the current The ratio of is the ratio of the resistance It will be the opposite. which is the ratio of the current The resistance ratio will become the opposite. Now the total current is 15 amperes. Total Current If If it is 15 amperes then you must know this much maths What will be I1? I1 goes into three parts and there are two parts to go in I2. total There are five parts, of which three This ratio of 3:2 out of five means It will be divided into five ratios. You will get a total of three I1 will get two more and I2 will get two. This means that Isn't it? So 3:5 How much total do we have in Intu? 15 These There is maths. Total is 15 amperes. out of that Three parts will go from this and two parts Will go out of this. three parts out of five In I1. This is R1. is R1. This is R2. from R1 went to I1 and this gave to I2. So, i1 is what Out of the total five parts, three parts are his It will be done. How much did it cost to cut it with this Brother? Three. 3*39 ampere will run through it Across. And if I2 is to be found out in the same way, then the total There are five parts. two parts of it Will go out of this. In total there are 5 parts Two will go from. By the way the current is 15 amperes. This resulted in a deduction of five rupees. to this by Kata three has arrived. 3 * 2 = 6, 6 amperes Went. And could have taken it out anyway. If its Across nine has arrived. If total is 15 then minus Even after doing that I would have got six rupees. but yes this is a proper one There are questions related to Maths and Physics. I would like you to repeat this question Do it. This is quite a lovely question. Good There is a question. This type of question Now let us come to the exam. Is it done? to the video You can pause and repeat it if you want. Moving Forward Are. The next question is coming from A Temperature Connected, which is what we did. Meaning Formulas have been done. a silver wire hedge Resistance. a silver wire The resistance is 2.12 ohms. When the temperature 27.5° It was Celsius. and resistance of but Its resistance is 2.7 ohms Went. when the temperature reached The one who reached, how much did he reach? 100 degrees Celsius has arrived. You should have a temperature Coefficient of resistivity, that is, you Alpha needs to be calculated. The Alpha Formula Do you remember? I just did it, so it's very easy. If you don't remember the formula then look around the world Use your strength. You will not be able to solve it. What Was it a formula? I will miss you brother. the formula was R2 = R1 which you can also call R0. 1 +α T2 - T1 we have everything. How much is R2 Is? 2.7 How much is R1? 2.12 This is NCERT question Is. You have to calculate 1 + alpha. t2 our pass is 100 and t1 we have 27.5. No need to convert. Also taught chemistry. Solution I am also telling you here in the chapter that someone it is not needed because the temperature You have to calculate the difference here. Ok? So from here you will get 2.7 / 2.12 this one will become minus is equal alpha and the difference that will come here will be How much will be the difference if 73 or 72.5 It's 72.5 right brother? from here look ahead Do the calculation of . alpha will come so much degree celsius inverse we have Alpha will come. by dividing it into one Minus it and then divide further. so much maths You do it. We have come to learn physics. I have not come here to learn maths. It is done. Will be done. This is a lovely question. Let's move ahead. Good question. It is very easy. but do not know Why do kids get confused in this too Are. Once again let's understand what he is saying Question. what is the largest voltage that You Can Safely Put Across a Register Across a register? How much is the register? 96 ohm and 1 watt means the power you get is 1 watt I have given it. That is, 1 watt and 196 ohms What is the maximum voltage you can get across Can you do it? Very simple. see how? What It would be correct for us to say that the power We have used the formula for voltage and resistance What did you read in the form? Multiple of Power The formulas came. Work done / time I² R, V² / R and I in V* so which one am I here Will you apply it? V² / R so the power formula is V² / I will put R. We have one power. R we have 196. here came my near V² then I have maximum V which is It has to be taken out which will be this. So maximum V 196 will come to me. 196 maybe 14 It is square. so from here I The voltage will be 14 14 volts. How much This is a lovely question. No much fuss Is. Just by looking at the largest voltage, child Gets nervous. Largest voltage means Maximum voltage. Maximum Voltage Means Maximum power and maximum resistance you have to take. then the maximum power is one and The maximum resistance is its rating Is. Do you understand the meaning of rating? Marked Rating means the maximum that it is Parameters can be maximum Resistance maximum its power. So this Its maximum voltage was reached. It's simple. Ok? Come. On to the next question. a uniform Wire of resistance 20 ohm. a uniform The wire is 20 ohms. which was cut to In equal parts. then these two parts Hey this is a question of LKG. lkg question Is. There is a wire. This is a question about LKG. and this The resistance of the wire we have is 20 ohm It is Om. It is 20 ohms. We divided this into two equal parts Divided into parts. We gave it to Divided into equal parts. one one this The part is done. We divided it into two equal parts Gave. One part is done, and the other is this The part is done. and we have both parts Connected them with each other in parallel. Both we connected the parts together In parallel. I did this in parallel. Now You obviously have resistance to this Have to take it out. Do you know physics this much again? It will be. If its 20. If its length is l And it is 20. If the length is reduced to half. his If the length is made l / 2. the length of If is made l / 2 then the resistance length K is directly proportional. So if If its 20 then its will become 10 ohm and Its going to be 10 ohms. and in parallel you will get Do you know how to solve it, friend? So 1/r The net will come to 1 / r1 + 1 / r2. So 1/r net will come to me 1/10 + 1/10 Basic maths says it has come to me 10 / 2 then r net will come to me 5 ohm. I have also told you a short technique If it wasn't there then I will tell you again. whenever If equal resistances are connected in parallel Their net is halved. if 20 20 If it had taken it would have been 10. Isn't it? it was 50-50 So it would have come to 25 lakhs. If you are engaged for 10 then Five has arrived. Simple question. Let's move ahead. Hmm. Nice question. Come on nice question. It is said that there are three identical resistors We have. R1, R2 and R3. These are identical There are registers. This question is the winner It is from the series. This is question winner series It is of. Isn't it? I also have this question I have brought it from the Winner Series. Isn't it? and this This question is also in Winner Series MCQs Those who are. MCQs will also come in Winner Series Of. So we have created the winner series in this manner It is designed. Right now we have all the questions I am not able to get it done here. Paid Batches are happening in. But we have won the winner series It is designed in such a way that you A little more on competency based questions Be able to focus. So right now I'm here a lot I am not even bringing any difficult questions. Because I have two children, son. the first one shot They come for pay revision. and the other forests People come to the shot only to read. He never The chapter is not read at all. Isn't it? Or If you teach him, he becomes completely blank. So it's difficult for them right at the beginning It would be a little weird to come up with a question. But it is obvious that you all know it Like last year, this year too we are here If you go live then we will give you better service there We will ask better questions. last class year that you can also see live classes in papers No, I will talk about the time before the papers too. I have been. Ok? and this year we have more Good questions will have to be asked. because The physics paper that came last year was a lesson for all of us. I know, it was quite difficult. So his You will have to practice. and for that's good excellent competency based Winner for Question Level One Level Two You can purchase the series. you know the link where is it in the description will be. There are three identical resistors R1, R2, R3. Now since these are identical, these The resistance of all three will be equal. beginning I can also start them with R1, R2, R3 You can. But it is obvious that all three Are equal. So we take this as R. Is it okay? Yes. What do you have to do? To you We have to find the ratio of voltage across R1 and R2. Here we have R1 and here we have is R2. We have to find the voltage across them Is. well i would name them something Am. Whenever we add something to the diagram by ourselves If we bring changes then we need to see the diagram You have to read it in your answer sheet. So Whenever you do this in your answer sheet I mean in the exam because now I am here Gonna do some labeling. give some names I am going to. So you have to read it. So I call it A, I call it I'll give it B, I'll call it C and I will call it D. So first I what am I doing? Look across the AB We know that there is total resistance R Is. So the resistance across AB is R Is. R1 means R. But if the resistance Looking across CD, there are R2 and R3 That means R and R means 2R here There is resistance. That means this whole The resistance is 2R. It is very simple and its The resistance is R. Now you know this too that whatever current comes out from here, Current will also flow out. That here and that here, divide will be. There will be a divide here and there. But The cross emf of both will be EE. Isn't it? E will remain. but because here If the resistance is double then the current will be halved. You know this much, right? The resistance here If it is double then the current will be halved. I hope so So you know if I ampere comes out from here then there will be two pieces of I. If both of If the resistances were equal, then I / 2 and I / 2 would have gone. But it is not like that. Whatever current is going here lets go to I1 And whatever current is going from here through the lets I2 We all know. because the one here The resistance is still there, I am still behind you Got the question asked. The resistance here is double If it is then the current will be halved. That means so much We know that I2 is half of I1 will be. Because I2 has double the resistance So the current will be halved because the power is same. What do we have to do? Voltage Across R1 and R2 has to be removed. The voltage ratio is I want to find the ratio of V1 and V2 Am. It is very simple, how? what is the voltage It happens? Resistance to current into. Then R1 is The current across is I1 and the resistance is Its R and the current across it is I1/2 is the same thing right I1/2 and its The resistance is also just R. I2 in this too He will go to this also. Now we have no idea about R3 There is no need. Its work is done. Son The world is like this. When it is used its Throw it away afterwards. Isn't it? So, what is the value of R3 Work is a deep talk. O. Ok? Well, R to R It got cancelled. I1 to I1 cancelled out. So the ratio of V1 / V2 is what we have It would have been 2:1. It would have been 2:1. here comes the. Is it done? So this is how we can solve this lovely question Can do it. That means you understand that we Small concepts. Now this is the same question asked by a 10th class student. It will be given to the children in the class. so maybe Get stuck. means 50% children will do it but Can't do 50. because its little things It is looking like this here. but a 12th class This is what the teacher expects from the child in board exams He is doing this so that you know even the smallest things. You will learn a little English. Age Resistance Of a CD is double. so according to ohms law Current will be half. So do it in English You will have to write a little bit in the exam. Come on, let's move on. Hmm. In the given figure, Ah in the given network, calculate the effective Resistance between A and M. That means you get A And across the M means leaving this 10 one You have to give it. Across A and M only Total resistance has to be found out. Now, because There is a lot here. So here we This needs some naming. There is a lot. There is a lot. So I tell this R1. I'll call this R2. let me tell this one R3 let me tell this one R4 Let me tell it to him R5 It's here near R6 it's come to us near R7 its just now I don't need it right now but it's R8 Okay, now which series and which parallel You may be seeing both of these in the Bhaiya series If it is in then let's deal with them first R1 and R2 If these are in both series then first R1 and R2 should be dealt with, come on I will call him RA I will tell you. Ok? A no no A It would be wrong to say that. A is someone's name. So R12 Let me tell you. Is it okay? Then R1 and R2 which Yes, it is in the series. So how much did you get? 10 And it came to 10 20 ohm. Ok? After that its The R12 that comes is in parallel with R3 Is. Isn't it clearly visible? In parallel. This What should I name 1/R? R I will give you X. Ok? give me anything No. So R12 means this one which is in the series of both. That and this R3 are in parallel Went. So it becomes 1/R3. Ok? So 1/RX I have arrived. 1 / R12 means 20 and that too how many what is it? 20. I just told you it will be halved. So RX comes to us at 10 ohms. Now whose RX is this Did the resistance come brother? So this is the RX of these three. He has come after meeting me. now here it is again It is in the series. again in the series with Is. So I am naming it RY. So RY This is RX and that means the net that comes from it That and the R4, it's in the series. and which R4 Yes, it is in the series. so 10 + 10 again Our 20th has arrived. Stuck back in the loop Brother. They are going reverse on us with. Come on brother. Let's move ahead. We are now this the answer that has come is this one, this one the answer This one has come, its net has come i.e. that the ry that came is with our r5 It will be parallel. So let me call it 1/r d which is parallel with 1/ry + 1/r5 will be. It will be parallel. then again 1 / r d then watch the same from 1 / 20 1 / 20 again in the loop He trapped us and brought us back again I gave only 10 ohm. That means R D now I am going to do this I have solved the whole thing. Now one or two Only one step remains. Now the R dash is The R Dash that came with the R6 It is in the series. So I'll call this R double dash. which is R D + R6. again 10 and 10 20 has arrived. 20 ohm arrived. But this time the This one we have is 30. this time half It is not going to happen. and last but not the LEST 1/R FINALLY USED BETWEEN 1/R AM I will get it in. It will be available in the middle of the AM. i.e By solving this and this we have got 20. Now Whatever we have got R double dash, it is its The Across will be in parallel with R7. So 1 / R' + 1 / R7 So 1 / Ram Oho, this has become Shri Ram ji. and 1/R' It's 20 and here's R7, how much does it cost Did it go to us? 1 / 30 now 30 and 20 How much LCM do we have brother? Ah 60 has arrived. 60 has arrived. 60 has arrived. This If we subtract this, we get three. From this When we cut this, we got two. so here From R Across AM Will Come to Us 60 / 5 That is 12 ohm. So congratulations, son. So much After all calculations, our across AM The resistance has reached 12 ohms. Across the AM Across the AM is okay, right? Is it done? But The work is not finished yet. beacuse you Power supplied by the battery has to be removed. If I need to remove the power supply by the battery, So I have the total voltage and from here I can find out the total current. near me is the total voltage and from here I get the total current I can take it out. How to find the total current Can I? I have total resistance to that. should would. I will not even get a good current will work. Because if I have the total If the resistance is found and the total voltage is The formula V² / R can also be used. Correct Is? So finally now R net is given in the whole circuit It's time to take it out. R across the circuit It's time to take out the net. Then A to M Across that which we have called Ramm. Plus we have this resistance We did not see this in R8 Plus then Was. look and here we have R9 so this All three will now be in the series. this is AM All that is left is that we have done it on the net. So this, this, this, these all came in the series. So The R9 guy has also joined us in the series. We also have the R9 coming to us in the series. So This is what we have received 12. We have this 10 and one we have eight. we have this 10 and one we have eight. So this is 30 ohm We got net resistance. that's over The question is done kids. Now we have to calculate the net power Have to take it out. So the formula for net power would be How much is V² / R²? 36 meaning square of 6 is 36 and R how much do we have Is? 30. Take this, son. we have so much power I have come. What a lovely question. Full Fledged Question. Number three full flanged Question. This is a question from the winner series. You will enjoy doing it. The concepts too will be clear and this is a very difficult question too Not there. It is not a very difficult question. It is done. Ok? Come on let's move ahead. Come Go. Some MCQs are coming. a wire of Resistance 160 ohm is melted and drawn In wire of 1/4 of its length. See if I melted a single wire and cut its length has been increased to 1/4. either melt it or If you increase its length by pulling it, then the volume So it will remain fixed. Sometimes it is said that We took 2L length of wire instead of l length Is. So the area does not change in it. We took the wire of double length. But Here we have pulled the same wire either Or if it is melted then its length changes If it is there then the area will also be there along with it. As much The more you increase the times length the lesser the times area because keeping the volume constant It happens. So if we melted our hearts for you and we have made the length 1/4 of that, then Its area would have increased four times Only then this must have happened because the volume A constant has to be kept. Ok? Now The formula for resistance is Ro LL / A. Now you have this common sense that the material So you might not have changed it. So your length is l / It becomes 4 and your area becomes 4a. 4 and 4 It will become 16. So the new Resistance Roll / a time will become 16. That is, the new one This is resistance, it is the old resistance will be reduced by 16 times. 16 times less than 160 It was already there. decreased by 16 times. 10 ohm is The Answer. 10 ohms is the answer. 10 ohms is the answer. so this We will get 10 ohms. then say it again I am pulling and melting such a length If we change it then the area also changes. As many times as you have not understood this Look at the area into which length adds volume Is. So with the new area and the new length Whatever volume comes, it should be the same. So If your a and a d ratio is like this then Here the ratio of l' and l will be like this. i.e If you do whatever you want to do to the length, it will affect the area It will have the opposite effect. If you measure the length If it is reduced four times then the area increases four times Will go. If you want to remember this somewhere If you want to write, you can also write. Ok? Come. I think this is a 10th class question The child will do it too. You can also do it, it is easy. what is there in this son it doesn't mean that Is. This is P/Q only. You do not understand that If I am talking about 10th class then Why am I even getting it done? because this also to you You have to understand that these questions will also come. The Voltage V and current I graph for a conductor at two Different temperatures T1 and T2 are seen in the Figure. The relation between T1 and T2 is now Look what we told you? If this is any is a conductor. If this is a conductor. No If he has said so then we will accept that he is a conductor. So the resistance is dependent on temperature It will be directly proportional. if these If it is a conductor then the resistance of the temperature It will be directly proportional. if that is the case So whose slope is this one? Is too much? You all can see it. of T1 Is too much. If I consider this to be first Am. I am considering this as second then between V and I Slope provides resistance. R gets Is. I talked to him just today. Now if that is the case then It is clearly seen that the resistance of R1 is greater than that of R2 Is too much. The resistance of R1 is more than that of R2 Is. Now if the resistance of R1 is more than R2 If it is there then its temperature will also be high. Son In this question sometimes weight IV instead of VI comes I will give you the graph. I have talked and If the IV graph is given then it will be inverted Because then we get 1 / R from the slope. Now! At the moment T1 is > T2. It is done. These IV The graph is given. You know this is ohmic. Non It is ohmic. We have talked about it again. anyway This is the PN junction which you need to read. Moving forward into semiconductors. But yes this It is clearly seen that this is a non-ohmic conductor Is. It is a non ohmic conductor. Ok? A Battery is connected to a conductor. very cute Question. very cute my favorite questions One of. They are saying a non uniform Non Uniform of non uniform area of ​​cross section There is wire. Often we still have the wire here She lives in the same area from here. But From here on out it's non-uniform. from here It is more, less here or the opposite. And we've Connected it to a source. One Connected to the battery. Ok? One Connected the battery to it. Ok? Correct Is? You have to tell me which of these is is there a quantity or are there quantities which Whatever will remain constant will remain constant. Will the electric field change? yes The electric field will change. First You have read in the chapter Electric The formula for the field is force. Force Upon Or say the formula of electric field is the potential gradient. So you will go ahead So the electric field will change anyway It must be. So the electric field is very will do it. Drift velocity will also vary Brother. Because drift velocity area is It depends. I told you the equation of Consider this as a continuity of what we learnt in 11th I had explained it to you. Understand that the wire is what it is There is a pipe in which water is running. So From here also the water has to go in at the same time Is. Have to come out from here also. in this case Only there is current instead of water. So if from here If current is coming in then it will come out from here also It will definitely go irrespective of the area. So if the electrons are moving slowly here So there is less area there, so they I will have to come out quickly. because less area like this in 11th class pipe forward If pressed, water comes out quickly. So The drift velocity here will be will be more and the drift velocity here Whatever is there will be less. So this is not the answer either Is. Isn't it? current i electric current then But there is no electric field. So The answer is current only. Current only. Current only which is any area of ​​cross section ho will remain constant. It will be fixed. also stay Needed It is done. Come on come. this question I am giving you homework. Very Easy PG Lemon Whatever QG says we all say. These There is homework. This is a very easy question. Ok? These I am getting this question asked. but this This question is homework for you. Ok? Come on, this last question. After that, the crutches will run Of Law. The most important topic. After that I answered his questions in the same way as Crutch of Law. I have got it done in my own way. one or two questions in that I have got it done. Then over Wheatstone Bridge I'll ask one or two questions now. and then the series Cell series parallel one or two above it I will ask questions. more on top of that by not asking 10 questions but by asking 5 to 10 questions Will finish the chapter. then you properly Complete the chapter. in the comment section Will talk. Complete the chapter properly. Then the fourth chapter and then the first four chapters Question Answers in Live Classes of do. Promise. Come on come. Current Off 3 Ampere flow through 3 ampere current flow Used to be. From this one. Oh wow! from this one A current of 3 amperes is flowing. So you The power has to be taken out across this one. Oho Wow! What a roundabout question this is. Voltage I have not given it. three amperes across it going. You need voltage across it Have to take it out. What is all of this about? what's the matter Hui? It was a very nice thing. Does it From resistance and its current we get voltage I will get it. and the voltage across it That will be the total voltage also. be careful Hear If the voltage across it is V then V1 across this will also be V. Its Across is V2, that will also be V. In both of these It will be divided because it is in both the series but There will be same thing in it. So V1 means the voltage across it is actually We will also have our net voltage. Its Across which because voltage is same in parallel It remains. so the voltage across it is Our total voltage will also be that and the voltage Formula of Current Into Resistance It happens. The current has given us three more You have also given resistance to this. so total It became 5 volts. it means just here I made this change so far the total voltage Given used to come. We had to remove it here. Ok? Now you have to remove the power through Across it. Now if I have to calculate 3*2 of it then Is Ashu doing it? what is ashu doing? What Is Ashu doing it? Have you gone mad? drunk tax Have you kept it? Are? I don't drink coffee What? 3 * 2 is making 5. tell me is it my Owner. we we It is six o'clock, Babu what are you doing? Correct Is. It is six. Let us look now. We have to What to take out across? voltage drop Is. If I find the voltage across it, then I have to find the current across it It will have to be Its what I call Lets Say I3 I have been. I need to find the current across it and the total resistance before current will be Will have to take it out. So this one is in R net If I want to find the R net of this one, then And 5 will become 6 ohms. So across this which The current will come, it will happen to the current The formula is V/R. Now, the V is across this across this across this across everyone It will be across. and V is the same in parallel Is. So if its resistance is six then Voltage 6 I. Resistance six arrived. So Congratulations to whatever current passed across this. Congratulations. The current that passed across it It became 1 ampere. Now if its across current It became 1 ampere. If the current across it is 1 It's ampere. So take out that power It's children's work. Power Formula I* contains V. Across which I am going that is 1 ampere going and the voltage which yes that's six. so congratulations 6 volt its o sorry 6 watt 6 watt across it No. I have made some mistake here. The resistance became five and one six. Did right and then the voltage is V / R V we have How much is it? It is six. Yes that is correct. of power The formula V* contains I. yes so these 6 How did I put V? It is wrong. No No. Power formula V * not i It will look like here. No. Power formula in V* how will it look? r is we have and i is. Sorry. Then i² R will be taken. Isn't it? a question I made two mistakes. anshu you did not pay attention These days you are focusing on studies. Isn't it, son? i²r will it come here i²r will come here sorry pe i has come to us one and i our come closer look i mistakenly put the i in v* before I put it why am I saying it's wrong because we have i but our there is little across these individual v which I took v six that is total right So there is a total in the individual series If it is different then i² r formula will be applied and here r what we have is five Is. So five plus one here we get 5 watt answer Will go. 5 watt answer will come. Yes. Good Six was not even in the option. well that is Let's see it. but in option There wasn't six anyway. But it doesn't matter. Five watts is the answer. Done. Let's move on Are. Krachhoff's Law increases. After that, V Stone bridge is the most important. Crop Law's I will also ask questions. There are two laws. be careful Reading. and after that we series parallel Voltage emf will question that. So quickly first. Ok? It's done brother. Now let's finally talk about this chapter about the most important topic that We have Krachtoff's Law. So Crutchoff G has two laws. The first law is Krachoff's law Of. This is also called the First Law and this Also called junction law. what does this law say Is? That statement is written in English above It has happened. But this law says that accept our There is a junction near here. Meaning of junction Do you understand? Where some wires are connected to each other I am meeting you. So don't assume this here There is a junction. In which I1 current comes from here Used to be. From here I2 current comes towards the junction Used to be. And here comes the I3. I4 is coming out from here and from here Exiting I5. Isn't it? or even There may be multiple wires. so junction law It says that the more current comes towards the junction The same amount of current also leaves the junction Is. i.e. the total current entering the junction is always equals to total current leaving the Junction. How much current is coming towards the junction The same amount of current is always released from the junction It happens. According to this, I1 and I2 are Both currents are coming towards the junction. So Who will these be equal to? Of I3, I4 and I5. Isn't it? Of I3, I4 and I5. Now you can say it like this You may say that the junction law says that as much current It is coming and it will go as well. Or if you are in Bring everybody here so you can speak like this That is the net current at the junction is zero. because Whatever comes, goes too. So Current never stays at the junction. net The current remains zero. but this statement It is much better. the sum of currents entering A junction is always equal to sum of currents Living That Junction. Isn't it? in a way Remember 11th class equation of continuity. Nothing can last here. As much as the current Whatever comes, will also go away. now question on this How do you come? Take this question. In this gave you the values ​​I1, I2, I3, I5 and He said, remove I4. So he comes to take it out Will go. It is very simple. Well, if you Ask Junction Law is based on what? So Junction Law: This question also comes up a lot. is Based on law Off Conservation of charge. Junction is law based Law of Conservation of Charge Pay. which says We created the charge in the first chapter I can't do it, I can't destroy it. So Junction law is basically based on the law of Above the conservation of charges only. Isn't it? Whatever charge comes, that much will go. so from there Came. As much current comes, so much current will go. But The main law which comes to us. Hey, hey Well, it is not written here. We by hand I will write. The main law that comes to us On top of which big numericals appear. This We say or you can call it Crutchoffs. Krachoff's Second Law. But it also has another name which we call loop Also known as Crutchoff's loop law. These what do you say brother? it says The Total Potential Drop is always Equate Two total Potential Gain for a loop And a circuit means one circuit and one loop The more the potential drop in the potential Across what does the drop fall? Resistance Across the. the more the potential falls Across the resistance, the same potential There will be gain also. Where does the potential arise? Cell Or across the battery. We will understand this now in a better way, but it says The more the potential drop, the more There will also be potential gain. Now by understanding this First we need to understand some four sign conventions You will also have to understand it first. Ok? Sign What needs to be understood in the convention? would accept it we have these in a circuit The resistance is R. and the current flows in it like this It is happening. Now the current is in one direction I must be flowing. Isn't it? and right there Assume that the resistance R is same and the current flow in such a particular direction It is happening. Ok? rectangle. Now if you are a Whenever we apply the loop law in a circuit so what we'll see is that we'll either move clockwise We will go either clockwise or anticlockwise, it makes no difference it doesn't matter if we go clockwise anticlockwise but let's say if I take a I am going in a direction and that direction It is in the direction of the current. I am a I'll go to the circuit now. Now if I change the current If I go in the direction of The potential drop will be obtained which is V = IR it will have to be taken in plus if I want the current I am going in that direction. But if I the current is going here but I Should I go opposite to this, which I will tell you right now? It won't make any difference. But if I were to If I go opposite then I will have to take IR. this to you You might not have understood it either. Understanding from a circuit I will come. but for now just understand that if If you are going in the direction of the current You have to take drop + IR. and if you take the current If you are going in the opposite direction of You have to take the drop - IR. Exactly like that. If we talk about gain then across whom is the gain will be? It will be across the cell or battery. Correct Is? Its emf is let e and here it is a cell its also emf we have e now If you connect a positive to negative in a circuit how do you go to the terminal It depends but if you are going from the positive to the negative terminal there is gain in that you will take -e but if you you go from negative to positive You would have taken + positive if you had gone be it from positive to negative then you will take -e if If you go from negative to positive then you will get +e Now to understand this, we will ask a question here Let's make it. What does the question mean? a circuit Let's take it. Late I have one here The circuit is something like this. Ok? I had this circuit. Its The resistance is some let's say R1. some of this too Let's assume R2. Its emf is E1 and its The emf is E2. Ok? This is a plus. these plus Is. And let's assume that here the current is He is running like this. because this circuit There is only one. So here at the moment there is current in everything It will be the same. And the direction will also be like this. Ok? Now in this question you are given Came. Suppose here you have got the words of Mr. Krichoff Loop law has to be applied. So it will be your choice do you go clockwise in it or You go anticlockwise. This is your choice. Ok? You please check it. If I move clockwise If I go there you will do the same thing anticlockwise go and do it. Your final result and mine are the same will be. Ok? let us suppose i go I go like this, i.e. clockwise. Ok? Memory Keep. I'm going clockwise. this is me I am going. You can also go anticlockwise yes. if I go clockwise then The potential drop is always greater than the potential gain It will be equal. Krichoff's second law says that the total potential drop is always Equal total potential gain. now where is the drop Is it happening? then the drop happens after r Across. so first I went here if suppose here Let me start with. then the drop is IR That means there is potential IR. So this happened IR1. I'll take the minus for the plus. current goes here and I am also going clockwise. I can start from anywhere. From here Let me start. Suppose go clockwise If I am then + IR. Ok? I'll go here again So here also the current is flowing here. Me too I am going here only. So I will come again R2. If you were going the opposite way, this would come - Is IR1 or IR2 ok? now you go here If you are going here then there is no one else There is no resistance. So the drop has happened. This is the drop. Now we will write the gain. Now If you go for gain then where do you find the gain? Cell Or across the battery. So I came here. Here You are going from positive to negative. So Going from positive to negative you need to take -e Is. So it becomes -e1 . But come here, come here, come here. so here But you are going from negative to positive. So When going from negative to positive you Have to take it positively. So this is the sign convention. Now this is the equation we have. Look at Physics This is it. This is physics. maths is obvious It is a thing you know there is a lot in it is involved. now 1 2 3 4 5 six variables Are. Someone will give you five, ask you for the sixth I will take it. How do those maths questions come? You know. But this is a very basic question Did. Now, suppose you go here Anticlockwise. So here comes the minus. Here There would be a minus. A minus comes here. here Plus comes and here is minus. So you minus If you take it and make it common, if you cut it then it will be the same again The equation will return to where you started. So it doesn't matter if you Go clockwise or anticlockwise. Understand this much first. Now you are a little bit Complex circuits are also available. Little Let's take a complex circuit. As Let's assume we have this, r1. This is r2, okay? by doing this and here also we have This is it. Ok? I'll give you everything else Am. This is R1, R2, we have R3, we have I have E. Here we have R4. these are ours Have R5. This gives us E1. so this E2 is done. And here we have the R6. Ok No? also give the direction of current To you. From here let us assume the current is I1. I1 came, I1 came. Here comes I2. Ok? Now I have come from here. Ok? so now this You know it's all one wire. So If there is I3 here then there will be I3 here also And here also there will be I3. because this The entire wire is the same. now this is a wire If there is I2 here then there will be I2 here also will be. Now this because there is only one wire. Here If there is I1 here then there will also be I1 here and here The pay will also be I1. The whole contains I1. If wire is one then. Ok? Now I've given you a The graph is given. what to do quickly? What do you have to do? Listen. Listen to the task first Take. Then pause the video and do it honestly From. The task is that you have the power to complete this I am saying graph in graph. In the circuit I1, I2, I3 are three variables. So you All three have to be taken out. Isn't it? Accept everything else There is a given in the question. R1, R2, R3, R4, R5, R6, E1, E2 these are all given. just you I1, I2 and I3 are to be found. so obviously c The thing is, maths says that if you have three If there are variables then you have to make three equations Must be. Ok? So how do the three equations Will you make it? Listen. In the first equation I will make it as per junction law. If I go to this junction Let me look carefully, this is a junction, right? These This is also a junction. This is also a junction. So I am talking about this right now. So this If we talk about the junction, I would give it a name Am. let's talk about A B C D E and F are at junction A at Junction If we talk about junction A, then which ones Is there current flowing? So you look carefully. So I1 and I2 are coming here. This I1 is coming Is. This way I2 but the one going away is I3 Is. So I1 + I2 here will be equal to I3 Of. So this becomes our first equation, which is We made it using junction law. Now two more equations Needed So once I work on the top loop I will do it. Once on the bottom one. on the top I will do it. you do it on the bottom one We will match again. Let's do this. Ok? Come Now let's go through these loops A B C D D A, right? in loop a b c d a else if take such a loop If I am going then let's assume that I am going hmm clockwise okay come on so potential Write drop then potential gain from here When I started, I got a drop I3 And R3 is IR, will it give a plus, minus a plus I will come wherever the current is flowing I am going. Come here. come here brother So here I so again where the current is going That's where I'm going. I3 R1 Plus go here I am here I3 R2 plus some more there is nothing there is nothing come here I have gone here again, there is current here If I am going here then will you come I2 R4 you If we went the opposite way, all these would have become minus again It won't make any difference so I counted 1 2 3 4 do it always 1 2 3 4 dropped. Now this This is the only gain in the whole circuit Is. Isn't it? How am I going to get here now? If This is how I am going from negative to positive I am going. from negative to positive It is positive. So, this is the second one I have The equation is formed. Now you should quickly Loop hey we will go a f no, we walk in reverse like this. That means F, A, D, E, F, right? F A, D, E, F go. Walk quickly. This way Go so that your answer matches mine. This way Go. Make the equation. please pause the video Do this and make the equation. Request is then match do. Otherwise, you won’t understand. do it quickly Such work. Ok? It's done by pausing the video. come on come on now Let's make it with honesty, only then will you be able to learn. Now how many drops will I get? I'll get one, I'll get two I will get three. but we have two gains It will happen this time. So first let's look at the drop here. Are. then I1 R5 I1 R5 This is where we got a drop. Got the drop. Look here, here. now if you look here The current is going here. But I have the opposite I have to go. So the minus will come - I2 R4 - I2 R4. Come here. Come here. Come here now. The current is here. I'm going here too I have been. Which current is it? I1 is. Here I2 Was. Here is I1. keep this in mind. then I1 R6 I1 R6 so here brother we have one two There were three drops. It becomes three. Now the gain is two. If I am going here then I can go from positive to negative I have been. The opposite is happening. So -e1 will come. And here I am going from negative to positive I am going. So I will go from negative to positive So it will become + E2. Now there is maths next Brother. Is it okay? We will do that too. But For now there is a Rich of Law. Three equations Is. There are three variables. It will be solved. Understanding Went? Find the value of i1. here and here Put it. So two operations of the form i2 and i3 Equations will come. then do the elimination, Make whatever substitutions you feel like. butt yes This is an equation we have. Now my What will the request be? You can watch the video here Pause and go back to when I built the circuit Was. again because I didn't remember It must have looked like this. Again, their equation is Make and match. Only then will it be fun, otherwise it will be fun will not come forward. Ok? So Mr. Krachoff's Junction law states that at a junction the total What will the current be? Zero. and the loop law says that the total potential draw is It is equal to. And if I were to use a pay note here Should I write the points on which this law is based? Like this was law based on the law of conservation of Pay the charge. So this is based on the law of conservation of energy pay. We can call energy as crate or I can't destroy it. so as much as The more the drop, the more the gain. then this Law is based on law of Conservation of energy. This question is asked a lot in the exam, Bhaiya Let's ask about one or two numbers. is critch off revise the law because if without criche If we move forward after revising the law then this game we are playing I am going to study wheat stone now, not this You will be able to understand that you understood but not Wheat Stone ji You will understand if you go ahead without reading then you will get Vet You will not be able to understand the stone and another question will come It is very important to come from Stone ji okay okay please read this quickly Then let's go to the wheat stone, that's for sure so brother what is wheat stone bridge Brother, now the first thing is the Wheat Stone Bridge son wheat wheat stone bridge when you hindi If you translate it, it sounds very funny. But The Wheatstone Bridge is named after Wheatstone and his It is named after this. Actually Wheatstone The bridge is a five resistance bridge arrangement which is useful in reading meter bridge It helps. aldo you probably know Meter bridge has been deleted from our syllabus Is. Potentiometer is also from our syllabus It has been deleted. But the meter bridge is one such There used to be a device through which we could Calculate resistance to unknown substances You can. So the Wheat Stone Bridge is Actually, in making a meter bridge He helped me and many other things He solved it. but you do that slowly You will learn in your life. But before that you It is important to know that a Wheatstone bridge is What is? Obviously it is Wheatstone You will also gradually learn the applications of bridge. You will learn. but for now that's a whetstone Is there a bridge? So a Wheatstone bridge is five There is some arrangement of resistances in this by type. Like there is a resistance here Fitted to. There was a resistance here It has happened. there is a resistance here Is. And there would have been a resistance here Is. And the wire in the middle has a The galvanometer is attached. Obviously C The thing is, if there is a galvanometer, then there is no There will definitely be no resistance. so here There is a galvanometer attached to it. So Now I am resisting such an arrangement Let me assume P, let me assume q, Let me take the value of R and let me take the value of S. So what a Wheatstone bridge is basically These five resistances are something like this Arrangement is made. Now this arrangement You will gradually learn why it is special But we have to read Vstone Balancing In condition. Now what is this balancing condition it occurs? Is it okay? what happened to you Balancing condition brother? Come let's check it out. So here let's say I applied V volts Gave. I turned this switch on. Correct Is? what I told you that on Tuesday we People will take over live at 8:00 p.m. inside of it I'm going to come with two to three questions. Am. Ok? Now current came out from here II Current came out from here II this I current here Went. I went here. Now current flows through this I1 went from Lets and I1 came here from Lets I2. Now we read the junction law. Assume here Pay I1 is going. Accept it and let's go I1 is becoming Is. Now as I1 gets here something The current will come down. Joe from Let's The current in the galvanometer is IG. You Consider it as I3. We assumed IG. go like this Used to be. Now IG will come from here. From here I2 So here both these currents will be added. So I can also write this as I2 + IG. Now Because here I1 was going and out of that IG If it goes here then the remaining part i.e. I1 - IG Isn't it? Suppose 5 amperes were coming here. Four went here so the remaining one i.e. I1 - IG will move here. And back from here It will come because it has been read to you. One Resistance in a circuit The current remains the same. In one wire. Now this which They are actually making arrangements What is? So you can understand the Wheat Stone Bridge Went. Weistone Bridge is a special type Arrangement of five resistances. But What do we have to read? We have to read Balancing condition. Balancing Condition Off Wheat Stone Bridge. balancing condition of Wheatstone Bridge. The Hum of Wheatstone Bridge People have to read the balancing conditions. These What is this thing, brother? Come let's check it out. The balancing condition says if IG is zero, that is, if the center pieces Now if what you are calling a galvanometer Current from the center piece i.e. galvanometer goes to zero so the ratio of this to this upon This should be equal to the ratio of this to this goes. Understand if current through central Resistance and current through galvanometer is Zero than the ratio of corresponding Resistance is equal. That means if IG is zero If this happens then the ratio of P / Q is R / The ratio of S i.e. P / Q is R / For S and obviously it is P / RQ / S It will also become equal. You know this much maths It will be. So we will prove it now and This is one of the most in this chapter This is one of the important derivations. If I. is zero then p/q remains equal to r/s. We have to prove this. Have to prove it. Now How to prove it brother? come here is the proof Let's see. is very easy. Krachoff's Law and we also need to revise Krachoff's law Will go. So you could name it something like this here are green in colour. Let a is b. this is c and This is D. Ok? Now, if I talk about these Loop a b da is it in loop a b d and I should go like this Like I am taking a loop i.e. clockwise so today taught you that potential drop is equals Where will the two potential gain drop in this There must be some resistance to this as well Its resistance will be called g. okay and this is three drops and gain There is no gain at all in this whole circuit You can see there is no gain anywhere If this happens then it is an obvious thing If it is equal to two then zero will come on this side. So If we move here now then its current is I1 and If the resistance is P then according to IR I1 P Done. I am going in this direction. I'm going here so its resistance is G Accept it. So I am in the same direction, IG G will come in into. Ok? and I will come here If I come here it is a minus. if the current is here I am going here - I2 It will become Q. This is the drop. Three The resistance is drop. How much is the gain? Zero. Ok, now tell me is IG G zero? If If IG is 0 then I1P + 0*G + I2Q = 0 now here oh sorry minus was this my bad my bad we had this minus Now if it comes here then it will come to me From here i1P i1P = I2Q I have this one The equation will come which I will solve now I am saying that the first equation is correct, which Why did I put IG on this loop and set it to zero? Because this is what we have to prove that if If IG becomes zero then we will get this and this It is very useful. Think about it if I tell you The current is going to zero from the middle and this If you come into balancing condition then its up this this upon this if the ratio is equal So if you don't know the value of any one If you know it and you know the rest, you will find it out And anyway it is very useful indirectly Going to do. Ok? Now let's go into the loop It's B C D B, right? in the loop B C D B goes in a loop. Ok? Now If you go in BC D loop I will come here. Here I'll get the drop first. of current I am in direction. How much is the current? I1- IG I1 - IG into resistance into How much is its resistance? It is R. this is it Gone is the drop. I will come here. drop here too Is. But I am going against the current. If I am going opposite then - current in S into How much is it? It's I2 + IG, right? I2 + IG minus Why did you take it? because in opposite direction Am. Ok? because now look from here too If I want to go opposite then IG minus is required. Will go. So - G will come in IG and into How much is equals two? 0 now again if If IG is zero then it comes to I1 - 0 Here comes i2 + 0 and here comes 0, this is complete I have become zero for myself. Is it okay? Now If this is so then what has happened to me here? i1 R and here I had a minus Plus I2S is done. who do we have here now Is? I1P, here is I2q. Here is I1R and here is It is I2S. Consider this, both the second equations Divide by . The work is over. The work is over. Dividing First and Second Dividing First And divide it by second brother. so what is this Is? I1P and I2 here we have I1P /I1R is done. Is this it? and what is here Went? I2q And I2S. I1 cancels out I1, I2 cancels out I2. what came Tell me went? p / R = Q / S. But, we have to I had to prove it P / Q R / S hey friend what I talked about small things. Take it in the reverse direction. Reverse Take it. So P/Q bring it here. This Take it here. R/S has arrived. And this to us I have to prove it brother. i.e. V Stone Bridge which is a special arrangement. These It says that if the current through the center piece goes to zero If this is / then the ratio of this is upon this If the ratio is equal then it will be equal. whose There are benefits in going ahead. Now if I talk What is the difference between emf and internal resistance? Relation will read its graph. then we have Cells will come in series and cells will come in parallel Our one shot for today will end again. But these three are very important. So Relation between emf and internal energy Resistance of cell. See what it is? Our so you understand that we have a is the external resistance and this resistance I applied an EMF across here Gave. Isn't it? Plus minus emf. now you just What were you doing till now? You were thinking that this is the emf. That is R. current in the circuit Used to be. But tell me what are you thinking? In the comments There is no need to even write the answer. think and tell me Do you think a battery is made up of one cell There must be some resistance inside, right? It must be happening. We call it internal Resistance. The name suggests internal Resistance means the one which is denoted by small R Let us show you. How much resistance does a cell or It is inside the battery itself. his too There is some resistance. then they show no it is but it is and we call it with small R Let us represent you. Now the emf and the How to build a relation in internal resistance Remove? So late the amount came here The current is flowing. Income Amount Off current is flowing. Ok? This way By doing. So we will apply Kruchoff's law. Here Two cases will be made. the first is Discharging. Now what does discharging mean? What happens is that you are using the cell. You are using the cell. in Chemistry in Electrochemistry You must have learned how to charge a cell as well goes. So when you charge then the current The direction becomes reversed. because we If we charge it then the direction of the current It gets reversed. Normal case for now Yes, discharging is taking place. We mean this are using it. discharging is taking place Is. This is a normal case right now. Ok? if so If it is so then we will apply Krachoff's law. From here As I am going, IR is coming. If I am like this If I go, IR is coming. IR plus what else Is there any drop? One resistance is here Is. And there is no resistance, right? hey it is Why not? There is resistance inside it Internal R. So you will get a drop here. So What drop will come here? IR R will be small. So this is the drop. Now this equals two What do I have to put here? Gain. If I have come like this, from gain negative I am going positive. negative to positive If I go, I will get a positive result. Ok? Is it done? So we have here E The formula is IR + IR, here the R This is the external resistance that we have applied which can also be called load resistance or is there any appliance whose this There is resistance but what is small R It is internal resistance, okay now what is IR IR is V according to Ohms law i.e. If its potential difference is then emf V + IR is done now tell me have we achieved this At the beginning of the chapter we read that emf is always greater than the voltage then the answer See how it increases. because IR is being added to it. Ok? First talk. other thing. What is this E? EMF. V What is? Voltage. Voltage Drop Across This is the load resistance. and I is the current in IR And R is our internal resistance. These Keep this in mind. Another formula from here also comes. This is the usefulness of E's formula What? I R + R this is a very basic formula Is. But we are mainly behind it. How? If I derive the formula for V from here If I want, will Formula E - IR of V come? Now you don’t even know how much You have derived the important formula. How? Here we will make a graph. now and Son, you should watch the pyqs of last 10 years. There is no need for you to agree with me. I Who am I? watch last 10 years pyq Take. Look at at least the last 10 years At least 3 years. This is a very big number. 3 This year only this flower came up for question Is. Whether it is related to the graph. whether There should be a direct question. so here we go We are comparing. if you have maths Then you will know the equation y = mx + c i.e. From the straight line equation. who doesn't know Whenever somebody is in the form that a There is a variable y then there is a variable x in x what are we going to make i and here There is an intercept c which is a constant then This is called a straight line equation, easy In language if I plot v on the y axis i.e. Create potential Create current on x axis So this m is the slope, so According to this, our slope is coming On comparing, the -r is coming which is the slope What is happening is -r. This simply means that that the graph which will be formed will be as below will come. The graph that will be formed will move downwards And why is the graph downwards? Because the slope is -r. Because the slope is - r because the slope is -r. So if the slope minus r then the graph is here. Now what would this be Is? c Intercept. Intercept Mean Graph Where does our y axis hit? so this It will collide here. i.e. this is the emf and It should also happen. Because v's maximum The value is called emf. Now on top of it Will ask the question on Tuesday. gave the graph You must have it. He must have given you this slope. They will ask you R or E. Anything will ask. So you should know this when I will plot the graph of V and I, then it will Sloping downwards will come. Constants The slope will be - R because R is constant. But if it is in minus then the graph will move downwards Will come towards you. Did you understand this? It is done. You sure Is. So this is the relation. well we did that Who is it for? For discharging. If I will do the same for charging. Of note I am giving you points. if this is the work then charging I will do it for you. By the way our charging Very few cases come in physics because these This is electro chemistry. Butt if charging If I am doing this then change the direction of the current will go. So nothing will change. the one who has -i In its place will come just plus. i.e. the formula of V It will become E-IR, right? Why minus? Because the direction of the current has changed. Minus minus becomes plus. So, E + Iir It will happen and nothing will change. Equation Same will remain. But this should be your main focus. Done? Let's talk about the rest, end of the chapter. Enough I feel this is a big one shot. Is No? Come on come. Ok. Sale in Series and Sale Let's talk about these parallels. Ok? Now As we have discussed resistance in this chapter, connected in series and the resistance in parallel I applied it. in the previous chapter capacitors are connected in series and Capacitors were installed in parallel. Just like that You should keep in mind that in this chapter, we People put cells in series and cells in parallel I apply it in. Done. Now put the cell in series What does it mean to apply? come to me some There are cells. Look, I want to ask you another question. I will ask and after that we will talk about it When are cells connected in series and when in parallel When do you apply it? When to sell in series Do we apply it and when do we apply it in parallel? Ok? Who is this one that we have? these are ours We have three cells that we put in series has given it. Does everyone know how things are in the series? The current will go to the same or say positive Negative. We connected here Is. Ok? Now its emf is E1, its Its emf is E2, its emf is E3. Its The resistance is R1, its resistance is R2 And its resistance is R3. Ok? Correct Is? Ok? Ok? Now This was a series combination. parallel like this There is a combination. then we will understand that Which combination is used in homes? And is the other one even used? that or not. Ok? Let us go. So here we have a parallel combination. What will be the identity of parallel combination Brother? Positive will be connected to positive. Negative will be connected to negative. Isn't it? As it happens. Now in the resistance If positive was not negative then it would have been like this We couldn't do it. This is positive, It is positive, it is positive, it is negative, It's negative, it's negative, right? So this is parallel The combination is done. Its emf is E1, Its emf is E2, its emf is E3. Its The resistance is R1, its R2 and its R3 Is. Got it? Now what is there here brother? It's sorted. what is there here? If the current It is flowing from here. So I am everyone's It must be flowing across. But the voltage It will be different across everyone. its cross The voltages will be V1, V2, V3. but here at What will happen? If the current I drawn from here is So I1 must have come from here, I1 must have come from here I2 and I3 must have come from here. and resistance So I have given it. Now, first of all, let us understand that Where to use series and parallel combination It happens. Like I can tell you one of the best parts of this Let me give you a good example. For that we Should I stop the camera? Isn't it? I'll give you this I will show you from close. Let's look at this first. Now as you look here once. So These two cells are a normal remote It is ours. now how to put a cell inside it Look what happened is we have a negative terminal here we have the positive terminal No, now I put the sale here like this After this what's next I have here It is positive, now see this negative from positive If it is connected then it is a series combination because I saw this here in the remote If you want to use the cell then click here Series combination is installed, now you think We must have had a remote like this in our house if it is there then what happens in it then here the same thing happens if I open it sec one sec yes this if I put this here But if I open the door then you will feel that friend It looks positive here but Here the positive is inverted. so like this Does not happen. Actually upside down from the inside It is only negative. like it here I have the negative. this this part It is negative and this part is positive. So I put it here. Now when I see this If I take it out from here then this is actually here Both of these are connected with each other. So here if I connected the positive then Now I have to connect the negative here. So these two are connected from inside There are. So you might feel good but actually negative to positive connected will be. So this is also a series combination. So we all knew that we were going to play the series at home Where do I use it? In the cell. Cell It is used in series. But now this Look, you may not find this in your home. Because this is a cell charger. here we sell and while charging we will charge it We will have to give them the same voltage so that they can Charge on voltage. so what are we Let's do it here in parallel combination We are applying it. look now here I The negative flat one is negative right and This Thunru that has come out is positive It happens. so i see here it is negative Placed it down. Now to charge the next cell as well I'll have to put the negative down and Positive up. then for the next one too Negative down, positive up. Like this to me all If I have to charge all of them It has to be done on same voltage. I use them You should not do it. I need to charge these. I will go and put it on charging now. all of these The cells will be charged. the first thing is In chemistry, you must have read that charging happens The cells containing these are different. and which does not charge They are different. To these we It's called primary. These are secondary but they There is chemistry. to charge this We always use parallel combination. Is it okay? yes did you see where we were Where do we use series and parallel combinations We do. Actually in short you can say this It is possible that whenever we use the cell you have to use it like a remote etc. So we would have put it in series there Are. But whenever we have to charge the cell If it happens then we have to give them the same potential it occurs. So parallel. because now you are at home You don't charge your cell phone often. Me It seems that cells are being used in 99.99% of homes Are. You never charge the cell. I don't think whatever you have done in your house I saw someone has the charger. Very little will be. Someone might have some requirement. Any Maybe if he uses a lot of cell. Otherwise there are very less chances. And In Short the point is that you probably understand this You can't find it. Isn't it? Now series and parallel The total emf is ah and the total How does resistance come about? Look now If I talk about series combination in sale So the total resistance is very common sense the thing is that I would get R1 + R2 + R3 because if the cells are connected in series So the resistance is also connected in series will be. And here if I take out R net then I will get 1 / R1 / R2 1 / R3 Do this and sleep on. But how to find the emf? So it is obvious that here the emf Just like if I had 5 volts And one is 5 volts. If I them If I put them both in series then five more You'll get five 10s. That means here we know that What will happen if the EMF is straight? Add E1 + E2 + E3 it is obvious that Derivation can also be done. Butt for now There is no need. Isn't it? Isn't it? Obviously C The thing is, it's not like this somewhere There will be no derivation in physics. butt For now you could say that Joe EM Should I get its derivation done also? See It is very simple. do it similarly Take. Look, if I tell you that here If there is a series combination then it is across everyone The voltage i.e. V1 V2 V3 will be different. As That we use in series. Then V The net will come. Isn't it? now this formula What will happen if I say V? I-IR then V What will be the net? E net - I R net because V The formula is this. So just like this V1 What will happen? What is E1 - I R1 V2? Say What will be E2 - I R2 and V3? Say. E3 E3 - I R3 now if you look from here, E net - In I R net E1 + E2 + E3 so on and - I What will happen if I take the common one? R1 + R2 + R3 That's what I was saying. Now compare E The net came equal to this, right? E net its It came equal. and R net comes out to be equal to So we can work through comparison method. But if they are connected in series then the net R You will take it out like this and you will take out E like this. But If it is in parallel then know the R net But the formula for calculating E net is a little different. It is complicated. What is that? E net / R NET formula can be found here. E1 / R1, E2 / R2 and E3 / R3 do the same comparison You can. If I give you a start Because here I = I1 + I2 + I3 Because the series was in combination. Voltage Once added, the current gets added in parallel. Isn't it? Now from here if you calculate the formula of I You will find the formula of I for I. of I What will be the formula? E - V / R so from here E net will come - V / R net will come from here E1 will go - V1 / R1 will come from here E2 - V2 / R2 Now actually V is the same. So Here you can write V1. Here you can see V1 You can write. V is the same. and here Here comes E3 - V / R3 again separate the two. Compare it and you will get the same. Ok? We have now Krachoff's Law has two laws inside it and its Ask some basic questions. again There are many good questions on Krachoff Law too. Are. We will do that dedicatedly. Very He also asks lovely questions. If I get it done here like this then one shot this It will take five to six hours. But yes, Read Series Parallel and know about Series Parallel Together we formed an internal resistance Also read off sale. Ok? So there is internal resistance of sale or its graph The questions that we have about this too do. Isn't it? then the graph should also be divided once We will discuss it in detail because the graph There are actually many questions about this these days I have started coming in. Many have started coming. So many have started coming that I don't know what to do this year He will not come. Because many are coming. Come Nor do we discuss it. Let's get started. First of all, we will talk about this question about. I hope you have all the formulas now I have remembered everything that we have done just this second I have studied in half. Is it okay? what-what Questions coming to us? first question comes There are two cells of emf 1.5 i.e. one We have an emf of 1.5 volts and the other one has The emf we have is 2 volts. Is it okay? Is it okay? having internal resistance to this The internal resistance is 0.2 ohms and The internal resistance that we have That's 0.3 ohms. ok look here He had fun. if the series had been called It was very easy. you saw E1 + E2 but If I speak in parallel then the work will increase a little. Will go. Calculate EMF and Internal Resistance. First, internal resistance We take it out because we need it It also appears in the formula for finding emf Yes, if you have remembered it. Now parallel then 1 / r net will become 1 / r1 + 1 / r2 Will be done. Is it okay? Yes. So I will give this 2 I can also write /3. I'll take the top 10. So Here I have it in terms of 2 and three LCM will come six. I have 10 upstairs Already happened. You must know this much maths. So If 10 has come here then 30 has come here It will go and I will get 20 here. So In total, the R net I have is my How much will come near? That R net will come to me I got 6/50. Isn't it? 6 / 50 has arrived. So I got the value of R net as 0.6 / 5 so 0.6 / 5 means 0.12 I have arrived. 0.12 has arrived. Yes. 12 ohm has arrived. Correct Is? This resistance has come. Now we have the net The resistance has been removed. a part of it So we did it. Now, its emf is What is formula net? Will remember. E Net / R Net = E1 / R1 + E2 / R2 Then if If you know the fool then there is no question Is. You have to take out E net. R net your 0.12 has arrived. E1 you have 1.5 And R1 you have 0.2. and you have this to And here you have 0.3. all of these You have the values. From here you can get E Net You will get the number of volts which you can calculate Take. i.e. a little bit in parallel Things get complex. In the series So we can directly do E1 + E2 and for R we can do R1 + R2 Let's do it. It would have been very simple. Is it done? Now here you have a very interesting There is a question. from this interesting question First, I will revise one small thing for you. I want to say that we just stepped back a little bit Some time ago I read a formula which said E = V +IR If you remember, from here if I I write V = E - IR and here if I put this I compare it with a straight line. That means y = if I compare it with mx + c I do it. if you got straight marks in maths If you have read the line chapter then from that equation and We have discussed this many times in Physics. Its graphs are often seen in chemistry too. has been created by. So you must have understood that the This is the axis on which we will get the volts. and x We will get current on the axis. So according to that Which will be the slope of the graph. m which happens That is a slope. So the slope of the graph is It will be -r . Voltage on y axis Went. Current came on the x axis. So slope has it arrived? - I have come. and the intercepts that come The intercept has come, e has come. i.e EMF has arrived. You have to understand this. any of the For any voltage and current, the graph You need to keep all these things in mind for the graph I will have to keep it in. Now if you keep this in mind If you can then come let's read the question. Four Cells of Identical EMF Internal Resistance R R connected in series to Variable resistance. The Following Graph Joe You have got what you have. now to the A part of it It has been said, what is the EMF of each cell? did I tell you that the intercept That gives you the total e. now this graph If you can see the intercept of 5.6 Is. So from graph from graph graph of If we look at it with the help of E net, we get What I am getting is 5.6 volts. But It is said in the question to install four cells And that is identical. So if you get E1 Whether to take out or E2 or E3 If you want to draw or E4 then that is E net It will be 1/4 because they are identical. So 5.6 It became 1/4 of. Which came to 1.4 volts. So The emf generated by each cell will be 1.4 The volts will come. We got that from Intercept Have taken it out. ok what did they ask you after that Is? Internal resistance has been asked. Now internal Resistance will come from the slope which is -r. So the slope of the graph is the slope of V and I is the graph in this case this one V and I Not there. Keep in mind that what is formed by Ohms law Is. It is made with internal resistance The graph of V and I is. So in this case which is the slope of VI graph for internal Resistance. That's going to give you a -R. We have discussed this. Now its slope is How to remove? There are many ways. height upon 5.6 in base or take two or 2.8 and take one Well, talk as you wish. So any height So the height we have is 2.8 if I I take it, the graph is going down so obviously This is true, your height will go in minus and up In base 2.8, the base is one. So The total answer is 2.8 ohm which comes to us. goes. I mean, you have to find the slope. So this which I have got it done for you, it is very useful. You can also see more questions on the graph above can be found above. such as this one There is also a graph. This comes back to the previous question have been. But you can also ask this question Let's make it. a straight line plot showing the Also terminal potential difference. again same The graph is all the same. You just need to know the internal Resist Hey, this graph is also the same. his So the values ​​are also the same. values ​​are also same Is. You just need to know the internal resistance here Have to take it out. So they have already taken it back Are. The internal resistance was 2.8. Is No? I have just marked that point here That's one at 2.8. This one is at 2.8. Isn't it? Or it's two at 5.6. Same thing Is. So our answer will be the same as what comes behind had come. That is 2.8 ohms. Come on come. going back They are behind. Hmm. Ok? it would seem clear There you have it, this wheat stone arrangement. It has a Wheatstone arrangement. is this wheat stone Is the arrangement a balanced arrangement? What Is this a balanced arrangement? the question is We will see but this is 10/30 so 1/3 more This 20/60 is again 1/3 i.e. this is balanced Is. If it is balanced then there will be no current inside it I am not going to go. That means the IG is zero is going to happen because these balancing conditions Is. Let us see what other questions have been asked. in The Given Figure Shows a Network of Resistance Name the circuit so form. This circuit is made what is its name? we all know the name Is. Its name is Veet stone Bridge. Its name is Wheatstone Bridge. Correct Is? what is the current flowing in the arm BD? Edge Wheat Stone Bridge Edge Edge Wheat Stone Bridge In short I am writing it is in balanced The condition is in balanced condition because it is in balanced condition is in balance Condition So the current which will be the current in BD arm I have just mentioned IG in the diagram It will become zero because there is a balancing condition. Ok? State to laws that you have read in this To find the current in the branch Will be. So in the second law we have the Krachhoff loop It's law. I will write it in full. loop of Krachhoff G is the law and is the junction law of Krachhoff G. You It includes loop law and junction law as well as Because the loop law is based on the law of Conservation of energy and junction law is Based on law of conservation of charge. So You can also write that in brackets. same thing Is. Is it okay? Is it done? So that is the question. I have not been asked to take out anything. This is a theory question. Any Numerical Not there. We have this proper junction law Question on top of it. The figure below shows current in A part of an electric circuit. The Current I You have to calculate this I current from here Is. Above the junction law of proper Krachhoff G Based. Come on here 2 amperes came. From here 2 amperes came. So 2 amperes came. as much as comes It goes that much. So give and give. so here will enter 4 amperes. One out of four went here. one in four I went here. So here we have 3 amperes left. will be. There would be 3 amperes left here. in 3 from 1.3 moved here. So 1.3 out of 3 Went here. So obviously it is 1.7 Amperes would be saved. 1.7 amperes would be saved. 1.7 amperes would be saved. So the value of I is 1.7 It became an ampere. very basic but exam This is the question that comes in. Taken from Winner Series Is. Let's move ahead. in the given figure the Balancing condition of wide tone in bridge. what of this we already know here Have you told me what the conditions are? Balanced There is a condition. This is a balanced condition. If The condition is already balanced. Then B is At higher potential. D is not at. if these If there is a balanced condition then in this one and in this There will be no current flow in it. Whose This means there is no current flow from here to here It is happening. This means the same potential I have come. There is no current flowing. Which means they have come to the same potential. So any of the two B and D can't be at. So B and D are at the same potential because There is no current flowing through it. It is done. ok come on. this question should be discussed Already happened. Come. Now this question is a bit This is an interesting question. A little interesting The question is. By looking at this diagram, you will It doesn't look like it's actually a Vette There is stone arrangement. But if I call this A Should I grab it, pick it up and bring it here? If I call A Should I grab it, pick it up and bring it here? a little carefully You will have to look at this diagram. I am here I am making three of these. these ones Three. These three. Ok? these three are I am still making it. have a little patience for this For the question. Be patient for this question Will have to keep it. Now listen, what I did in this case. that is I have this resistance I made this one, keep this in mind R then I made this I'm making a resistance of R and then I I am making this resistance R which I made three resistors here. Just now and this wire B is E so I'll move this wire here I've gone to B is this one connected to E okay? And I have made this point D and I have made this point C A point has been made. So what do you want to imagine Is? I just did this one, this one and this one The resistance that was created was created here Is. What am I doing now? Pick up this A I am bringing it out. If I pick up A If I bring it out then R and R this one R and this one The R will come out. If I call this A If I pick it up and bring it out then this one R and this one The one R from here and these two R from here will come out. Isn't it? This R and this R outside will come. will come out means here R will come and here also R will come and I picked it up and brought it here. Now you me diag ye I picked A up and brought him here To explain. Now if you look at the diagram If you watch, even the dumbest child will understand That this is a wheat stone bridge. he too In balance condition. Five Equals Resistances each of resistance R Connected edge shone. I have also given you the voltage If it is there then the current has to be extracted. take out the current We will take it but first remove the resistance It will have to be Now you tell me this is R/R's The ratio is equal to the ratio R / R Is. That means it is actually a wheat stone And in what condition is he sitting? Balanced. it means between this one It makes no difference whether the person is there or not It is happening. It means the middle one It doesn't matter if it happens or not Is. Ok? Who is this? R and R. Then And what is R? 2R is the top How much resistance do I have? 2R Then how much lower resistance should I have Has gone? 2R now the parallel of 2R and 2R In which did you tell about the current? Current Flowing In A F this is A. This is A. No, it is A. This is F. Ok? This is A. This is F. His Where to go after F? C. This is C And then there's E and B. So now look now. The current across it is 2R. Its The current across is o sorry resistance That is 2R and this also has 2R. So you From where to where has the current been spoken? have told you How much current will flow here? a little carefully Look I have told you how much current flows here It will be here. So if we divide this whole into V Connected with . Connected with V Is. So what is the formula for current? The formula of current is V / R. Now its voltage across it is same because it is connected to V. Then V its voltage is and its The resistance that has come is 2R. and below If total had been told then it would have been V/R because The upper 2R becomes the lower 2R. But Here it is called across current. So V/2R is the answer. Oye Hoye Oye V/2R Is The Answer. because we only have to cross across it Current has spoken. This is a funny question. Funny The question is. It is done. Let us go. So I hope you like this The one shot looked great. what are you doing now Is? a cute little one a cute little one a nice little Leave a comment to let you know the next one Who wants the shot? Chemistry is required. But do you need chemical kinetics? Or you want the next one shot HelloWeen, Hello Erin. Because before I Added one shot of electrochemistry. So now it's chemistry's turn. so who do you Want a one shot? Chemical Kinetics or Then HelloAken, Hello Erin you can send me a comment Tell me now on the section. Do like the video Do it and make a lovely comment and like So the reach increases. Reaching more children Those who need it will get it. I hope you I liked this one shot. Rest of the Winners Series Links to both Batch 1.0 and Batch 2.0 are below. From this will also read in a better way. let's catch up In batch. If not, you can read it on YouTube have been. Love you. Take care. Bye bye. have Fun.