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

Asked by Vishal kumar | 2 years ago |  188

##### Solution :-

Explanation:

The energy consumed by the appliance is given by the expression

P = VI = V2 /R

The resistance of the light bulb can be calculated as follows:

R = V2 /P

Substituting the values, we get

R = (220)2 /100 = 484 Ω

Even if the supply voltage is reduced, the resistance remains the same. Hence, the power consumed can be calculated as follows:

P = V2 /R

Substituting the value, we get

P = (110)2 V/484 Ω = 25 W

Therefore, the power consumed when the electric bulb operates at 110 V is 25 W

Answered by Shivani Kumari | 2 years ago

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