Question

In general terms, the performance of a system can be thought of as the output per unit input. The coefficient of performance K of any refrigerator can be represented mathematically as K=QC/W.

a) True
b) False

Answer 1

The statement is true; the coefficient of performance (COP) of a refrigerator is the ratio of the heat removed from the cold reservoir to the work supplied, represented by K=Qc/W.

Step-by-step explanation:

The statement that the performance of a system can be thought of as the output per unit input is true, and the coefficient of performance (COP) of a refrigerator can indeed be represented mathematically as K=QC/W, where K is the coefficient of performance, QC is the heat removed from the cold reservoir, and W is the work supplied.

In the context of refrigeration and heat pumps, the COP is a measure of efficiency, indicating how much cooling effect a refrigerator produces for a given amount of work. The higher the COP, the more efficient the refrigerator. This concept is deeply intertwined with the first law of thermodynamics, which includes the conservation of energy, and it's important to understand how heat transfer, work, and efficiency are related in cyclical processes.

The relationship between the coefficient of performance for a refrigerator (COPref) and the coefficient of performance for a heat pump (COPhp) can be expressed as COPref = COPhp - 1. This is due to the conservation of energy and the fact that heat pumps and refrigerators operate on the same basic principle but are judged on different criteria (the benefit for heat pumps is the waste for refrigerators).