Question

An electric bulb marked as 50v 200v is connected across a 100 v supply.The present power of the bulb is

Answer 1

The resistance of the bulb R = V x V / W = 200 x 200 / 50 = 800 ohms

The current through bulb at 100 V = 100 / 800 = 0.125A

The present power of the bulb = 100 V x 0.125A = 12.5 W