Question

An electric bulb.is rated 220 v and 100 watt power consumed by it when operated on 'no volt is:-

Options

• 25 watt

• 50 watt

• 75 watt

• 90 watt

Answer 1

25 watt

Explanation:

Bulb resistance = R = `v^2/P = (220 xx 220)/100` = 484 Ω

At 110 V, the power consumed is `V^2/R = (110 xx 110)/484` = 25 watt