Which of the following terms does not represent electrical power in a circuit?
$(a)$ $I^2R$
$(b)$ $IR^2$
$(c)$ $VI$
$(d)$ $V^2/R$

AcademicPhysicsNCERTClass 10

The correct answer is $(b)$ $IR^2$.

Power: The rate of the energy developed per unit of time electrical power in a circuit is known as power.

We know that $\boxed{P=V\times I}$  ........ $(i)$

Here, $P\rightarrow$power

$V\rightarrow$voltage

$I\rightarrow$current flowing

The relation between $V,\ I$, and $R$ is as follows

$V=IR$, 

Let us submit the above value in $(i)$

$P=IR\times I$

Or, $\boxed{P=I^2R}$           ......... $(ii)$

And we also know that $I=\frac{V}{R}$, let us submit this value in $(i)$

$P=VI$

Or $P=V\times \frac{V}{R}$

Or $\boxed{P=\frac{V^2}{R}}$         ......... $(iii)$

Equation $(i)$

$\boxed{P=V\times I}$ represents electrical power in a circuit.

Equation $(ii)$

$\boxed{P=I^2R}$ represents electrical power in a circuit.

Equation $(iii)$

$\boxed{P=\frac{V^2}{R}}$ represents electrical power in a circuit.

Relation $(i)$, $(ii)$ and $(iii) represents electrical power in a circuit.

But $IR^2$ does not represent electrical power in a circuit.

So option $(b)$ is correct.

raja
Updated on 10-Oct-2022 13:20:09

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