Question

Two electric bulbs whose resistance are in the ratio 1 : 2 are arranged in parallel to a constant voltage source. The powers dissipated in them have the ratio

• A. 1 : 2
• B. 1 : 1
• C. 2 : 1
• D. 1 : 4

Answer 1

The correct option is C 2 : 1

Power, $P=\frac{V^2}{R}$
As they are in parallel so, $V$ is constant. Thus, $P\propto \frac{1}{R}$
So, $\frac{P_1}{P_2}=\frac{R_2}{R_1}=2$ (given $R_1:R_2=1:2$)

$\Rightarrow P_1:P_2=2:1$