Question

Which of the following terms does not represent electrical power in a circuit?
a. ${\text{I}}^2\text{R}$
b. ${\text{R}}^2$
c. $\text{V I}$
d. ${\text{V}}^2/\text{R}$

Answer 1

Electric power is equal to the rate of electrical energy transferred per unit time.
The formula for electric power is: $P=VI$.......... (i)

From Ohm's law
$V=IR$.......... (ii)

Substituting the value of $V$ from equation (ii) in (i), we get
$P=\left(IRI\right)\mid$
$P=I^{2}R$......... (iii)

Substituting the value of I from equation (ii) in (i), we get
$P=V\left(V/R\right)$
$P=V^2/R$......... (iv)

The equations (i), (iii), and (iv) represent the electric power.
The option IR2 does not represent electric power. So, option B is correct.