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NEET2026PhysicsCurrent ElectricityActual

A room heater is rated 400 W, 220 V. If the supply voltage drops to 200 V, what will be the power consumed (approximately) ?

Options

  1. A200 W
  2. B400 W
  3. C331 W
  4. D121 W

Correct answer

C. 331 W

Step-by-step solution

The resistance of the room heater is given by R = V^2 P Substituting the rated values, R = 220^2 400 = 48400 400 = 121 When the supply voltage drops to V' = 200 V, the power consumed is P' = V'^2 R P' = 200^2 121 = 40000 121 330.57 W Therefore, the power consumed is approximately 331 W. Answer: 331 W

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