Question

An electric bulb is rated 220V , 110W. When it is operated on 110V , the power consumed will be

Answer 1

****Hey mate****

We know that,

P = V^2/R  

If V = 220 V we have

100 W = 220^2/R

R = 220^2/100 Ω = 484 Ω. This is the resistance of the bulb.

When V = 110 V, power consumed =  V^2/R = 110^2/484 = 25 W.

So, 25 W power is consumed when it is operated on 110 W.