FREE Air Conditioning Repair Refrigeration Cycle Principles Questions and Answers

Question 1

In a properly operating refrigeration cycle, what is the state and pressure of the refrigerant as it enters the compressor?

Accepted Answer

Low-pressure, low-temperature superheated vapor

Answer

High-pressure, high-temperature liquid

Answer

Low-pressure, low-temperature liquid

Answer

High-pressure, high-temperature vapor

Question 2

A technician measures a system's subcooling and finds it to be significantly higher than the manufacturer's specification. Which of the following is the most likely cause?

Accepted Answer

A refrigerant overcharge

Answer

A refrigerant undercharge

Answer

A dirty evaporator coil

Answer

A faulty compressor valve

Question 3

What is the primary function of the metering device in the refrigeration cycle?

Accepted Answer

To create a pressure drop, which lowers the refrigerant's boiling point

Answer

To increase the pressure of the liquid refrigerant

Answer

To absorb heat from the surrounding air

Answer

To compress the refrigerant vapor into a high-pressure gas

Question 4

A technician is diagnosing a residential air conditioning unit that is not cooling effectively. The suction line leading to the compressor is warm to the touch and the superheat is measured to be excessively high. What is a probable cause for these symptoms?

Accepted Answer

The system is undercharged or has a restriction.

Answer

The system is overcharged with refrigerant.

Answer

The metering device is allowing too much refrigerant into the evaporator.

Answer

The condenser fan motor is failing.

Question 5

Which of the following describes the process occurring within the condenser coil?

Accepted Answer

High-pressure vapor refrigerant rejects heat and condenses into a liquid.

Answer

Low-pressure liquid refrigerant boils and absorbs heat.

Answer

Low-pressure vapor is compressed into a high-pressure vapor.

Answer

High-pressure liquid experiences a sharp pressure drop.

Question 6

The fundamental principle of the refrigeration cycle is based on which thermodynamic concept?

Accepted Answer

The relationship between a fluid's pressure and its boiling point.

Answer

Heat is created by compressing a gas and destroyed by expanding it.

Answer

Heat naturally flows from a colder substance to a warmer substance.

Answer

Subcooling and superheating must always be equal for proper operation.