Question

If current in an electric bulb drops by one percent.Then the power decreases by

• A. $1percent$
• B. $2percent$
• C. $4percent$
• D. $1/2percent$

Answer 1

Answer: (B)

$2percent$

$P\alpha I^2$

$\Rightarrow \frac{\Delta P}{P}=\frac{2\Delta I}{I}$

$\Rightarrow$ If $\frac{\Delta I}{I}=1$

$\Rightarrow \frac{\Delta P}{P}=2$