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


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.

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