Question

You are given four bulbs,$25\text{W},40\text{W}$,$50\text{W}$ and $60\text{W}$. Which bulb has the lowest resistance for a given voltage?

• A. $25\text{W}$
• B. $40\text{W}$
• C. $50\text{W}$
• D. $60\text{W}$

Answer 1

The correct option is D $60\text{W}$

We know, power of an electric element,
$P=\frac{V^2}{R}$

$\Rightarrow P\propto \frac{1}{R}$ $[$At a given voltage $]$

$\Rightarrow R\propto \frac{1}{P}$

Therefore, $60\text{W}$ bulb has the lowest resistance.