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

The power consumed by an electric bulb is given by the formula P = V^2/R, where P is the power, V is the voltage, and R is the resistance. We are given that the bulb is rated 220V and 100W. Therefore, we can find the resistance of the bulb using this information:

100 W = (220 V)^2 / R

R = (220 V)^2 / 100 W = 484 ohms

Now, we want to find the power consumed when the bulb is operated at 110V. We can use the same formula, but with the new voltage:

P = V^2 / R = (110 V)^2 / 484 ohms = 12100 V^2 / 484 ohms = 25 W

Therefore, when the bulb is operated at 110V, the power consumed will be 25W.