Question

An electric bulb is rated 220 volt and 100 watt when it is operated on 110 volt the power consumed will be

Answer 1

Final Answer : 25W

We know that,
Internal Resistance of Bulb will remain constant.
R = V^2/ P = constant


=>
$\frac{ {(220)}^{2} }{100} = \frac{ {(110)}^{2} }{p} \\ = > p = \frac{100}{4} = 25w$