Power Loss Confusion: I^2R vs V^2/R

K Dhiraj Bhak · Mar 30, 2014

Power loss doubt: power loss = I^2 R Power loss = V^2 / R But the 2 equations are contradictory ,,, from the first equation , we can say " MORE THE RESISTANCE MORE THE POWER LOSS" from the second equation ,,, it is the other way round... Why does this happen? ( usually the 1st equation is used for power loss expression ,, but i don't know why ,, and i want to know why the second equation can't be used)

Doc Al · Mar 30, 2014

K Dhiraj Bhak said:

Power loss doubt: power loss = I^2 R Power loss = V^2 / R But the 2 equations are contradictory ,,, from the first equation , we can say " MORE THE RESISTANCE MORE THE POWER LOSS" from the second equation ,,, it is the other way round... Why does this happen? ( usually the 1st equation is used for power loss expression ,, but i don't know why ,, and i want to know why the second equation can't be used)

The expressions are consistent. The first one says that the more resistance the more the power loss if the current is held fixed. Just the opposite if the voltage is held fixed.

Power Loss Confusion: I^2R vs V^2/R

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