An electric bulb is rated 220 volt - 100 watt. The power consumed by it when operated on 110 volt will be

Options

A. 50 watt
B. 75 watt
C. 90 watt
D. 25 watt

Answer

D

Explanation

`R = (220)^(2)/100 = 484 Omega`
`I = 110/484 Omega, P = i^(2)R = ((110)^(2) xx 484)/(484)^(2)`
`= (110 xx 110)/484 = 25` watt