Question

An electric bulb is rated 220 V and 100 W. When it is operated on 110 V, the power consumed will be : (a) 100 W (b) 75 W (c) 50 W (d) 25 W​

Answer 1

Answer:

The correct answer is option no 3

Answer 2

Answer:

D. 25 W

Solution

We know the formula

P=V^2/R

100=^(220)2/ R

R= (220^2/100

= 48400/100 0hm

=484Ω

Now, the bulb is operated at 110 V, the power consumed will be

P=V^2/R

P=(110)^2/ 484

=12100/484

= 25 W