Question

the coefficient of performance of a refrigerator working between -10 degree Celsius and 20 degree celsius is
(a) 8.77 (b) 9.77 (c) 10.77 (d) 11.77​

Answer 1

The coefficient of performance of a refrigerator working between -10°C and 20 °C is 8.77. Optoin A is correct.

Explanation:

• Given data about working range of temperature

        $\mathbf{Minimum\ temperature(T_{min})= -10^{\circ}C = -10 +273 = 263 \ K}$

        $\mathbf{Maximum\ temperature(T_{max})= 20^{\circ}C = 20 +273 = 293 \ K}$

• Formula of coefficient of performance(COP) is given as below

        $\mathbf{COP = \frac{T_{min}}{T_{max}-T_{min}}}$

• On putting respective value in above equation of coefficient of performance(COP), we get

        $\mathbf{COP = \frac{263}{293-263}}$

        $\mathbf{COP = \frac{263}{30}}$

• On solving, we get

        COP = 8.77 = This is answer.

Answer 2

The coefficient of performance of a refrigerator working between -10°C and 20 °C is 8.77. Option A is correct.