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A refrigerator absorbs 2000   c a l of heat from ice trays. If the coefficient of performance is 4 , then work done by the motor is 1   cal = 4 . 2   J

Options

  1. A2100 J
  2. B4200 J
  3. C8400 J
  4. D500 J

Correct answer

A. 2100 J

Step-by-step solution

Q 2 = 2000   cal Coefficient of performance, COP = Q 2 W W = Q 2 COP = 500   cal W = 500 × 4 .2   J = 2100   J

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