Question

Suppose you have an ideal refrigerator that cools an environment at −20.0ºC and has heat transfer to another environment at 50.0ºC. What is its coefficient of performance?

a) 4.00
b) 4.50
c) 5.00
d) 5.50

Answer 1

The coefficient of performance (COP) of the ideal refrigerator can be calculated by dividing the temperature difference between the cold environment and the hot environment by the temperature of the cold environment. In this case, the COP is 3.5.

Step-by-step explanation:

The coefficient of performance (COP) of a refrigerator is defined as the ratio of the amount of heat energy extracted from the cold environment to the amount of work done on the refrigerator. In this case, the COP can be calculated using the formula:

COP = (Tc - Th) / Tc

where Tc is the temperature of the cold environment (-20.0ºC) and Th is the temperature of the hot environment (50.0ºC).

Substituting the values into the formula:

COP = (-20.0 - 50.0) / -20.0 = 70.0 / -20.0 = -3.5

Since the coefficient of performance can't be negative, we take the absolute value:

Applying the absolute value gives COP = 3.5