good evening good evening good evening good evening okay okay okay good evening good evening good evening very good yes evening good evening good evening evening booster booster christas s booster okay yes of course okay yes destion okay ready and also question of the day of the okay KSS congats okay okay ah King boy okay congrats congrats congrats King boy congratulations and celebrations don't worry full on powerful mil is the secret of energy okay deily flow of charges flow of electrons El [Music] what flow elow current is I I charge FL by time that is I equal to Q by T okay IAL Q by that I aage and I instant Del Del I instantaneous that is DQ by DT DQ by DT okay is the rate of flow of electric charges okay what is okay what is yes okay ready oppos oppos to the motion of negative chares negative negative char [Music] okay directly proportional to the Cent all the phical condition Remains the Same the potential difference across the ends of a conductor is directly proportional to the current flowing through the that is r i equal to V equal to I into r resistance they opposes current they oppos current flow current in flow in AAL I into r r is resistance which conductor will have high resistance when the both are made of the same material directly okay inversely proportional to clear clear or no inversely proportion okay equation this is a very important equation Ral L by a okay Christmas examination okay yes of the cond okay okay res okay of resistance unit of resistance okay of [Music] res ah okay okay met okay of a conductor depends upon resis yes very good it's material okay it's yes okay current at a point it is the amount of current it is the amount of current flowing per unit area around that point provided the area is in the direction of current okay CID i a i by a okay IAL I clear okay equation V equal I into r v = to I into R resistance that is Ral I okay V by L is equal to I by a into row if V by L Vol by volc by a that is j j i by a that is equal to J into Row 1 eal jity cond ah yes very good okay Sig okay Jal Sig Vector form clear clear crystal Vector okay Vector form of a law can be written as J equal to Sigma e the equation is equivalent from a famous law name the law that is OHS option b simple option b simple [Music] ready okay electr ROM okay plus U2 plus u3 plus up to divided by average AOC ready okay dire okay [Music] El drift velocity drift velocity okay velocity drift velocity is defined as the average velocity with which the free electrons get drifted in the direction opposite to the applied field opposite to the applied electric field first electric field chapter electric charges and Fields FAL Q okay that is Q into acceleration that is mass into acceleration is equal to e into eect this netive the electrons drift in the direction opposite to the electric field electric OPP okay velocity initial velocity U to V2 U2 + a into to2 V3 U2 + a into to3 elal u n+ a V1 V V2 + V3 + up to V nid N1 U1 + A2 plus u n + a n divided by U1 + U2 + u3 + up to u n divided by n+ acceleration to 1 plus to 2 plus to 3 + up to to n u U2 u3 U2 okay this is z to to 2 plus up to toid dri velocity veloc that is drift velocity equal a into drift velocity that is drift velocity drift velocity is equal to minus E E by m into to voloc that is relax rela relax relaxation it is the time between two successive Collision relax drift velocity velocity clear crystal clear yes okay okay yes ready okay okay I equal to V crosssection so much of electrons electrons electrons electrons electrons now suppose okay number okay total number of elect number of electrons okay capital N number of electr number elal number El div number of el area into length base area into L base are length L base area into length that is V is equal to a into L ready V ID a into L sorry n ID by n total number of electrons n okay volume of the conductor [Music] n is charge by divid by t l l by L IAL IAL V very very [Music] important what do you mean by drift velocity write the relation between drift velocity and [Music] electric it is the average current sorry it is the average velocity electrons in average velocity with which the electrons are drifted against the electric field velocity drift velocity is defined as the average velocity with which the free electrons get drifted in the direction opposite to the applied field okay set ready okay and IAL V okay I equal v i equal to V ready know I equal to V the current I the current of 9 amp is maintained in a conductor of cross-sectional area 1 cm square the number density of the free electron is 9 into 10 28 the drift velocity of the free electrons are 9 amp current is 9 a crosssectional are that is 1 cm s CM s s 10- 2 square 10 -4 M 10 -4 10 28 elect 1.6 into 10us a that is equal to I electron charge 1.6 into 10-9 N 9 into 10 28 and area of crosssection 10us 4 19 28 19 28 9 9us 4 that is 5 10 1 1.6 into 10 - 5 1.6 1 / 1.6 into 10us 5 0 62 5 into 10us 5 6.25 into 10us 6 6.25 into 10us 6 6 2 10 okay simple question rality velocity equation dri velocity drift velocity isus e minus EV by ml into to evid M IAL drift velocity and okay that is to a divid ml into okay V equal ml / n² to a into I sorry V mic resistance equal n e sare to n e sare to ml / by n m / n e s to equation important ² aity m/ to effect of temperature on Resistance andity ml / by n² to resistivity in equation m / n² clear number of s temperature increases more ELR number ELR okay Rel okay temp number of number of [Music] ELR okay cond cond already number of free ELR number of free electrons already el Dom temp okay already miss okay Miss full on yes okay on a cond semond semicon germanium already semond semond will be more set ready clear yes mang okay temp conductors semiconductors and the Alloys like nicro manganite [Applause] andang the type of materal yes very good that is semi conductors semiconductors write the relation between resistivity and aage collision time for the electrity equation resistivity is equal to m / n² to m n e to okay set ready clear okay ready ready clear yes cells cells batteries cells batteries cells and batteries different type of different type of okay MF okay it is a voltage electromotive Force current it is the potential difference between two electrodes or terminals of a cell when no current flowsent volage electromotive force is a voltage okay internal internal resistance internal resistance the resistance offered by a material of Electro to the flow of current inside the C ready internal resistance ready Elance then concentration of electrolytes then temperature of electrolytes okay this is our battery okay internal terminal voltage okay voltage CLE vol that is I into R is equal to e minus I into r i r+ i Ral em is I into r + Ral EMF e r okay IAL e r+ r e vus 1 okay R into external resistance into EMF / voltage minus one e equation okay I E Ral capital r into e / vus one capital r externally connected the resistance and E EMF of Vol teral Volus one ready set okay okay yes combination of a cell combin and [Music] okay E1 plus E2 internal resistance effective internal resistance r1+ r21 ready E1 R12 effec so E1 E2 that is equal to E1 6 EMF Vol EMF R effective R effective that is 1 + 2 3 okay okay okay [Music] okay okay intern effective resistance equ sorry effective em E1 by r1+ E2 by R2 / 1 by R1 + 1 by R2 okay e effective isal to E1 by R1 + E2 by R2 ided 1 by R1 + 1 by R2 ready okay effective internal resistance equation 1 by R effective is equal to 1 by R1 + 1 by R2 1 by R1 + 1 by R2 okay 6 1 that is E1 by R1 plus E2 by R2 / 1 by R1 + 1 by r21 E1 R1 E2 by R1 is 1 plus E2 3 by 2 divided by 1 by 1 + 1 by 2 1 by 6 by 1 + 3 2al 3 2 divid 2 + 1 3 by 2 2 2 15 by 3 that is 5 volt 5 volt in the get okay internal resistance equation that is 1 by R effective is equal to 1 by R1 + 1 by r21 that is 1 by R effective is equal to 1 by 1 + 1 by 2 1 + 1 that is effec 2 2 by 2 res clear equ yes ready clear okay [Music] v² by R into [Music] t v i t equational to i² r t e = v² by R into t e = v t okay ready clear yes power power equation equ i s r p equal v² R into I but p is = to i² r p is = v² by R and P isal V into I ready what is the power dissipated when 2 ampere current flows through a wire of resistance 5 ohm for 3 minutes into 60 that is 180 seconds 180 that is 4 into 5 into 180 4 into 5 is 20 into 180 36 Je that is 2 square into 5 4 into 5 20 Wat okay ready set that is first one is rules [Music] rule min Junction the sum of the current entering the junction will be equal to the sum of the current leaving the junction for four should be Junction 2 7 isal to 5 2 + 2 + I I equal 7 - 2 that is 5 a yes very good very good very good 5 okay ready five a of current okay a junction of electrical circuit is given below analyze the figure and answer the following okay what is the value of i1 and I2 I I value [Music] 1 yes very good very good very good i1 R okay current entering the junction will be equal to current leaving the state the law that can be applied to find i1 and I at any Junction the sum of the current entering the junction is equal to the sum of the current leav okay crystal clear okay that is Loop rule voltage law of the total poal differ okay NE vol find the current in each resist okay okay okay current i r i into 2 that isus I into 2 i i 2 I 2 I 5 IAL Z 5 5 IAL 10 IAL to 10 by 5 2 2 of current answer ready yes 2 ENT yes okay ready ready ready okay that is wheat Stone Bridge Okay wheat Stone Bridge very important okay to find to find an unknown resistance okay unknown BC R1 R2 R3 and R okay okay r okay [Music] okay galvanometer has null deflection null deflection def B banc brid Junction from Junction rule I2 equal I4 I I4 i1 is equal to I3 okay i1 is equal to I3 i1 is equal to I3 IAL I4 i1 okay yes okay this is Loop okay loop loop a b d minus I2 R2 minus I2 R2 gomet deflection that is plus i1 R1 equal i1 R1 is equal to I2 R2 in i1 R1 isal I2 R2 2 by i1 is equal to R1 by R2 first equation okay D okay DB c d loop loop DB C Direction minus that is minus I4 R4 in OPP plus I3 R3 is equal to0 I3 R3 is equal to I [Music] R4 by I3 is equal to I4 by I3 is equal to and the R3 I2 by i1 is equal to R1 by R2 then I4 by I3 is equal to R3 by R4 I I I that is R3 by R4 I i1 I2 by I R1 by R2 is equal to R3 by R4 R2 by R1 is equal to R4 Bridge equational okay a weone bridge is shown in the figureone bridge derive a relation connecting the four resistors for the galvanometer to give zero or R2 by R1 R4 by r [Music] equal R4 by R3 deration question in a circuit shown below assume that no current flows through the galvanometer find the value of resistance r okay 40 by r equal cross M cross multiply 20 into R is equal to 40 into 40 that is R is equal to 40 into 40 ided by 20 2 into 40 is 80 answer ready clear clear clear crystal clear item this simple and super easely s seven days booster challenge strategy okay okay question of the day question of the day okay question of the day semiconductor okay semiconductor temp [Music] okay okay bye bye love you all t t bye bye good night spe