TEXAS REFRIGERATION CONTRACTOR EXAM
1. What is the primary purpose of a refrigeration system?
A. To generate electricity
B. To transfer heat from a low-temperature area to a high-
temperature area
C. To increase ambient humidity
D. To compress air for pneumatic tools
Correct answer: B. To transfer heat from a low-temperature
area to a high-temperature area
Rationale: A refrigeration system works by removing heat from
a controlled space and rejecting it to a warmer environment,
using a refrigerant cycle involving evaporation, compression,
condensation, and expansion.
2. Which component in a refrigeration system raises the
pressure of the refrigerant?
A. Expansion valve
B. Evaporator
C. Compressor
D. Condenser
Correct answer: C. Compressor
Rationale: The compressor increases the pressure and
temperature of the refrigerant vapor so it can release heat in
the condenser.
3. What happens to refrigerant as it passes through the
evaporator?
A. It condenses into a liquid
B. It absorbs heat and evaporates into a vapor
, C. It becomes solid ice
D. It is filtered and cleaned
Correct answer: B. It absorbs heat and evaporates into a vapor
Rationale: In the evaporator, refrigerant absorbs heat from the
surrounding environment and changes from liquid to vapor.
4. Which refrigerant safety classification indicates higher
toxicity and flammability?
A. A1
B. B1
C. A2L
D. B2L
Correct answer: D. B2L
Rationale: ASHRAE classifications use letters and numbers; B
indicates higher toxicity, and higher flammability ratings
indicate greater risk.
5. What is the function of the expansion valve?
A. Increase refrigerant pressure
B. Reduce refrigerant pressure and control flow
C. Compress refrigerant vapor
D. Store refrigerant
Correct answer: B. Reduce refrigerant pressure and control
flow
Rationale: The expansion valve meters refrigerant into the
evaporator and causes a pressure drop, enabling cooling.
6. What is superheat?
A. Temperature of liquid refrigerant below boiling point
, B. Heat added to liquid refrigerant in the condenser
C. Temperature of vapor refrigerant above its saturation
point
D. Heat removed from air in the evaporator
Correct answer: C. Temperature of vapor refrigerant above its
saturation point
Rationale: Superheat ensures that only vapor enters the
compressor, preventing liquid damage.
7. What is the primary purpose of a condenser?
A. Absorb heat
B. Reject heat from the refrigerant
C. Increase refrigerant velocity
D. Filter refrigerant oil
Correct answer: B. Reject heat from the refrigerant
Rationale: The condenser removes heat from high-pressure
refrigerant vapor, turning it into a liquid.
8. Which tool is used to measure refrigerant pressure?
A. Thermometer
B. Manifold gauge set
C. Ammeter
D. Psychrometer
Correct answer: B. Manifold gauge set
Rationale: A manifold gauge set measures both high and low
side pressures in refrigeration systems.
9. What is the purpose of oil in a refrigeration compressor?
A. Increase refrigerant pressure
, B. Lubricate moving parts
C. Absorb heat from air
D. Act as refrigerant
Correct answer: B. Lubricate moving parts
Rationale: Compressor oil reduces friction and wear on internal
moving components.
10. Which law explains the relationship between
pressure and temperature in a sealed system?
A. Ohm’s Law
B. Boyle’s Law
C. Newton’s Law
D. Faraday’s Law
Correct answer: B. Boyle’s Law
Rationale: Boyle’s Law states that pressure and volume are
inversely related at constant temperature.
11. What is the function of a filter drier?
A. Increase refrigerant flow
B. Remove moisture and contaminants
C. Measure temperature
D. Compress refrigerant
Correct answer: B. Remove moisture and contaminants
Rationale: Filter driers protect the system by absorbing
moisture and trapping debris.
12. What happens if air enters a refrigeration system?
A. Efficiency increases
B. System pressure decreases
1. What is the primary purpose of a refrigeration system?
A. To generate electricity
B. To transfer heat from a low-temperature area to a high-
temperature area
C. To increase ambient humidity
D. To compress air for pneumatic tools
Correct answer: B. To transfer heat from a low-temperature
area to a high-temperature area
Rationale: A refrigeration system works by removing heat from
a controlled space and rejecting it to a warmer environment,
using a refrigerant cycle involving evaporation, compression,
condensation, and expansion.
2. Which component in a refrigeration system raises the
pressure of the refrigerant?
A. Expansion valve
B. Evaporator
C. Compressor
D. Condenser
Correct answer: C. Compressor
Rationale: The compressor increases the pressure and
temperature of the refrigerant vapor so it can release heat in
the condenser.
3. What happens to refrigerant as it passes through the
evaporator?
A. It condenses into a liquid
B. It absorbs heat and evaporates into a vapor
, C. It becomes solid ice
D. It is filtered and cleaned
Correct answer: B. It absorbs heat and evaporates into a vapor
Rationale: In the evaporator, refrigerant absorbs heat from the
surrounding environment and changes from liquid to vapor.
4. Which refrigerant safety classification indicates higher
toxicity and flammability?
A. A1
B. B1
C. A2L
D. B2L
Correct answer: D. B2L
Rationale: ASHRAE classifications use letters and numbers; B
indicates higher toxicity, and higher flammability ratings
indicate greater risk.
5. What is the function of the expansion valve?
A. Increase refrigerant pressure
B. Reduce refrigerant pressure and control flow
C. Compress refrigerant vapor
D. Store refrigerant
Correct answer: B. Reduce refrigerant pressure and control
flow
Rationale: The expansion valve meters refrigerant into the
evaporator and causes a pressure drop, enabling cooling.
6. What is superheat?
A. Temperature of liquid refrigerant below boiling point
, B. Heat added to liquid refrigerant in the condenser
C. Temperature of vapor refrigerant above its saturation
point
D. Heat removed from air in the evaporator
Correct answer: C. Temperature of vapor refrigerant above its
saturation point
Rationale: Superheat ensures that only vapor enters the
compressor, preventing liquid damage.
7. What is the primary purpose of a condenser?
A. Absorb heat
B. Reject heat from the refrigerant
C. Increase refrigerant velocity
D. Filter refrigerant oil
Correct answer: B. Reject heat from the refrigerant
Rationale: The condenser removes heat from high-pressure
refrigerant vapor, turning it into a liquid.
8. Which tool is used to measure refrigerant pressure?
A. Thermometer
B. Manifold gauge set
C. Ammeter
D. Psychrometer
Correct answer: B. Manifold gauge set
Rationale: A manifold gauge set measures both high and low
side pressures in refrigeration systems.
9. What is the purpose of oil in a refrigeration compressor?
A. Increase refrigerant pressure
, B. Lubricate moving parts
C. Absorb heat from air
D. Act as refrigerant
Correct answer: B. Lubricate moving parts
Rationale: Compressor oil reduces friction and wear on internal
moving components.
10. Which law explains the relationship between
pressure and temperature in a sealed system?
A. Ohm’s Law
B. Boyle’s Law
C. Newton’s Law
D. Faraday’s Law
Correct answer: B. Boyle’s Law
Rationale: Boyle’s Law states that pressure and volume are
inversely related at constant temperature.
11. What is the function of a filter drier?
A. Increase refrigerant flow
B. Remove moisture and contaminants
C. Measure temperature
D. Compress refrigerant
Correct answer: B. Remove moisture and contaminants
Rationale: Filter driers protect the system by absorbing
moisture and trapping debris.
12. What happens if air enters a refrigeration system?
A. Efficiency increases
B. System pressure decreases
