Question

An electric bulb is rated 220 v 110 w when operated at 110 v the power is

Answer 1

P = V2/R   If V = 220 V we have 100 W = 2202/R R = 2202/100 Ω = 484 Ω. This is the resistance of the bulb. When V = 110 V, power consumed =  V2/R = 1102 /484 = 25 W.

Answer 2

P = V2/R   If V = 220 V we have 100 W = 2202/R R = 2202/100 Ω = 484 Ω. This is the resistance of the bulb.When V = 110 V, power consumed =  V2/R = 1102 /484 = 25 W.