Question

Refrigerator transfers heat from the cold cooling coils to warm surroundings. Which law of thermodynamics favours this process?

Answer 1

Hint: Clausius stated that heat will flow spontaneously from hotter body to colder body. The second law of thermodynamics states that it is impossible to transfer the heat (or energy) from a colder body to a hotter one until an external force is applied. The coefficient of performance describes the effectiveness of the refrigerator.

Complete answer:
The second law of thermodynamics states that it is impossible to transfer the heat (or energy) from a colder body to hotter one i.e. non spontaneous process until an external force/work is applied. Refrigerators work on this principle as it transfers heat from the cold cooling coils to warm surroundings. In this case, the compressor applied the external work. The coefficient of performance $$(K)$$ describes the efficiency of a refrigerator. It describes the ratio of heat eliminated $$(Q)$$ by refrigerator to the work that had to be done for doing it $$(W)$$.
$$K={\displaystyle \frac{Q}{W}}$$
From the above equation, we conclude that an effective refrigerator will need less amount of work to eliminate a given amount of heat. If no work is done, then the coefficient of performance will be infinite which is not possible. Hence, a perfect refrigerator is not possible.
Therefore, the second law of thermodynamics favours the process of refrigeration which involves the transfer of heat from the cold cooling coils to warm surroundings.

Note:
It is important to note that the second law of thermodynamics favours the process of refrigeration which involves the transfer of heat from the cold cooling coils to warm surroundings. Clausius explains that heat will flow spontaneously from hotter body to colder body. In order to make the heat transfer from colder body to hotter body, we have to apply the external force.