Hello YouTube friends Welcome to a new video today we are going to learn what electrical power is or also called Watt's law [Music] Welcome in a previous video I had explained what mechanical power was today I am going to explain what electrical power is in reality the power is the same only today we are going to explain a little about what is the origin of being called electrical you can say that power is the energy consumed during a certain time we saw that mechanical power was classified as work over a period of time and remember that the work was given as force times the distance times the cosine of the angle theta between these two vectors between the force vector and the distance vector this work was given in jou and the time was given in seconds now let's see how in a basic electrical circuit which is the one we have represented here through this voltage source this resistor which is the one that consumes the current and the conductors through which the current flows then we can say that the power as I said now remains the same the work over a certain period of time now electrically it is defined the work as the work that must be done by the charges or electrons that circulate through this conductor we saw when we analyzed the subject of the electric current through this conductor or this electric cable internally because what are the charges circulate through there, that is to say a group of electrons that are flowing or that are being transported through this electric cable now the definition of work electrically is equal to this charges q multiplied by the voltage that is applied to the Source This is the definition of work a power is work over a period of time the current is defined as a group of charges that circulate through the conductor for a period of time now if we take this group that we have here in this definition charge over time is equal to the current Therefore we can say that the power is equal to the current times the voltage And that is the fundamental equation for us to calculate the power through Ohm's law remember that we said that the voltage was equal to the current By the resistance here of this equation we can replace then from here what is the voltage replacing this equation that we have here we have that power is equal to and we have this I that we have here and i * r Therefore we have that I * I is equal to i squared by the resistance And this is another equation that we can also use When calculating eh doing exercises of electrical power now from this same equation we can say that the current is equal to the voltage over the resistance now we replace in this equation we can say that the voltage is equal Sorry the power is equal to the voltage is equal to the voltage over the resistance therefore we have that voltage times voltage voltage squared over the resistance And this is the third equation with which we can use to solve exercises of electrical power in this order of ideas These are the three equations that we can use This is the fundamental equation and we have the two equations derived to solve exercises related to electrical power the power is represented by the capital letter W it is described as watts or watts Therefore they are the same units of the mechanical power we are going to learn it through the following exercise they tell us that a 60 W light bulb So these watts are power operates with a voltage of 110 vol they ask us how much is the current that the light bulb consumes and what is its resistance here we have our basic electrical circuit or to notice is that when we have this little circle through this little symbol that we have here it means that it is a source of alternating voltage like the one or a plug or an outlet that we can have in our homes and this is the light bulb that they are telling us that it is 60 WS they are asking us then How much current flows through the light bulb we have this little triangle to remember or facilitate the memorization of the equations by power is equal to multiplying B * I which is the fundamental equation that we already have here from this equation they are telling us How much is the current Therefore what we are going to do is clear the current and we are going to divide voltage to this blade here therefore we have that the current is equal to power over the voltage replacing the values mathematically power is 60 watts that the light bulb has over the voltage of the Source which is 110 operating mathematically 60 over 110 therefore it tells me that the current is equal to 0.54 amps now in the next exercise in the next one They say what is the value of your resistance therefore we are going to apply this equation they tell us that power is equal to voltage squared over the resistance we have the voltage we have the power we are going to calculate this resistor therefore what we do is pass it over here and this comes to divide in turn therefore we have that the resistance is equal to voltage squared over the power now mathematically replacing 110 volts we raise it to the square we divide it by 60 this gives us that they are 201.5 and the value of the resistance which is ohms therefore This is the value of the resistance that it must have to meet these requirements that it is giving us in the circuit this is all for this video if you have any questions or concerns let me know below in the comments box subscribe to my channel physics for everyone remember that we have different topics eh related to the subject of physics I invite you to stop by my channel check all my playlists remember always smile life and see you in a next video