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Concepts Of Physics MCQ Edition [Volume 2]PhysicsHeat Transfer

Using a 20 W heater, a metal ball of mass 1 kg is heated inside a room that is maintained at 20^ C . The ball's temperature eventually settles at a steady value of 50^ C . Determine the rate of loss of heat to the surrounding when the ball is at 50^ C .

Options

  1. A40 W
  2. B30 W
  3. C20 W
  4. D10 W

Correct answer

C. 20 W

Step-by-step solution

At steady state, the temperature of the metal ball becomes constant, which implies that the net rate of heat transfer is zero. The rate of heat supplied by the heater must be exactly equal to the rate of heat lost by the ball to the surroundings. Given that the power of the heater is 20 W , the rate of heat supplied is 20 J/s . Therefore, the rate of loss of heat to the surroundings at the steady temperature of 50^ C is 20 W .

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