A room heater is rated 400 W, 220 V. If the supply voltage drops to 200 V, what will be the power consumed (approximately) ?
- 400 W
- 121 W
- 331 W
- 200 W
Answer
(3) 331 W
Solution
Resistance of the heater stays the same: R = V2P = (220)2400 = 121 Ω
P' = V'2R = (200)2121
= 40000121 330.6 W ≈ 331 W
Answer: (3)