Explanation:
The Coefficient of Performance (COP) is a measure of the efficiency of a refrigeration or heat pump system. It is defined as the ratio of the desired output to the required input.

1. COP of a Domestic Refrigerator:
A domestic refrigerator is a common household appliance used for cooling and preserving food. It operates on the principle of the refrigeration cycle, which involves the transfer of heat from the inside of the refrigerator to the outside environment.

The COP of a refrigerator is calculated as the ratio of the heat extracted from the refrigerated space to the work input required to drive the refrigeration cycle. Since the desired output is the heat extracted, and the required input is the work done, the COP of a refrigerator is given by:

COP_refrigerator = Heat extracted / Work input

In a refrigerator, the heat extracted is the cooling effect achieved inside the refrigerator, and the work input is the electrical energy consumed by the refrigerator's compressor. As the cooling effect is typically less than the electrical energy consumed, the COP of a refrigerator is always less than 1.

2. COP of a Domestic Air Conditioner:
A domestic air conditioner, on the other hand, is used for cooling and dehumidifying the air in a room or building. It also operates on the refrigeration cycle, but with the added function of humidity control.

Similar to a refrigerator, the COP of an air conditioner is calculated as the ratio of the cooling effect achieved to the work input required. However, since an air conditioner has the additional task of removing moisture from the air, it requires more work input compared to a refrigerator.

The COP of an air conditioner is also less than 1, as the cooling effect achieved is typically less than the electrical energy consumed by the compressor.

3. Comparison of COP:
When comparing the COP of a domestic refrigerator to that of a domestic air conditioner, the COP of the air conditioner is generally less. This is because the air conditioner has the added task of dehumidification, which requires additional work input.

The COP of a refrigerator is typically around 3 to 4, whereas the COP of an air conditioner is usually around 2 to 3. This means that a refrigerator is more efficient in terms of cooling compared to an air conditioner.

Conclusion:
In conclusion, the COP of a domestic refrigerator is generally higher than that of a domestic air conditioner. This is because a refrigerator only focuses on cooling, while an air conditioner has the additional task of dehumidification, which requires more work input.