Question

Two bulbs each marked 100 W, 220 V are connected in series across 220 V supply. The power
consumed by them, when lit, is
a) 220 W
(b) 100 W
(c) 50 W
(d) zero
​

Answer 1

Answer:

(c) 50 W

Explanation:

The resistance of the bulbs can be calculated by using the following formula

P=V^(2)/R

R=484Ω

I=V/R=220/(2*484)=0.227 A

using P=I^(2)*R, we will calculate the power consumed by the bulbs.

P=0.227^(2)*484=25 W.

so the total power consumed is 25+25 =50 W.