Which of the following are principal parts in a closed cycle compression refrigeration system?

In a closed cycle compression refrigeration system, the principal parts are essential components that work together to facilitate the refrigeration process. The evaporator is indeed one of those key components.

The evaporator's primary function is to absorb heat from the environment (e.g., from the space or substance being cooled) into the refrigerant. As the refrigerant enters the evaporator, it evaporates by absorbing this heat, causing a temperature drop in the area surrounding the evaporator. This ability to absorb heat is crucial to the refrigeration cycle, making the evaporator a vital component in achieving the desired cooling effect.

The other components, such as the compressor, condenser, and absorber, play significant roles too, but the question specifically focuses on identifying the principal parts. The compressor circulates the refrigerant through the system, raising its pressure and temperature before it enters the condenser. The condenser then dissipates the absorbed heat, allowing the refrigerant to condense back into a liquid state. However, the question highlights the evaporator's role in initiating the cooling process, making it a principal part of the system.

Choosing the evaporator indicates an understanding of its foundational role in the refrigeration cycle.