Question

When the current in a conductor is doubled, keeping its resistance constant, the electrical power dissipated through the conductor will be _________.

• A. doubled
• B. quadrupled
• C. tripled
• D. the same

Answer 1

The correct option is B quadrupled

Power dissipated in a conductor is:
$P=VI=I^{2}R$

Since conductor is not changed, resistance $\left(R\right)$ is constant.
$⟹P\propto I^2$

Ratio of power will be:
$\frac{P_2}{P_1}=\frac{(2I{)}^2}{I^2}$
$\frac{P_2}{P_1}=4$

Therefore, if the current is doubled, the power dissipated through the conductor becomes 4 times of the original.