When three identical bulbs of 60 W-200 V rating are connected in series to a 200 V supply, the power drawn by them will be
Options
(a) 60 W
(b) 180 W
(c) 10 W
(d) 20 W
Correct Answer:
20 W
Explanation:
In series, Resultant resistance = R₁ + R₂ + R₃ = R + R + R = 3R
Power = V² / R ⇒ 60 = V² / R ⇒ V² = 60 R
Power of combination = P
P = V² / Resistance of combination = 60 / 3 R = 20 W