The Formula For Electrical Power Is (P=) I Squared R, And (P=) V Squared Over R. Why Two Different Answers?


2 Answers

amber Jhon Profile
amber Jhon answered
Basically the given explanation will make sense!

In fact, P = VI

In which,

P is the power in watt
V is the potential Difference in volt
I is the current in ampere

Now second Formula says that,

P = I2R = V2/R = V(V/R)

In this equation, Joule's law has combined with Ohm's law and the value of I has put in it because I = V/R. In the first equation, I and V are product and equals to power while in the second equation just the value of I has been put.

Now in the first case when Voltage will increase I will go down and in the second case the value of resistance will increase and again make the ratio of V/R equal to I in the first equation and it will not make any difference.

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