An electric bulb is rated 220 V and 100 W. When it is operated on 110 V, the power consumed will be:

Question

Philoid · Accepted Answer

The bulb parameters are as given below:

Power, P = 100W

Potential difference, V = 220V

Then Resistance, R = ?

Now,

This resistance of the bulb will remain constant i.e. 484

Now, when we operate this bulb on 110 V, then,

Power, P =?

Potential difference, V = 110V

And, resistance, R = 484

P =

P = = = 25 W

Thus, the correct answer is: (d) 25 W.