Page 1 of 164
Nevada C-21B Air Conditioning Contractor
Practice Exam 2025/2026 Latest Questions
& Verified Answers | Instant PDF
Download
Q1. Which of the following best describes the primary
function of an air conditioning system as defined for a C-21B
contractor in Nevada?
A) To provide complete building automation
B) To regulate indoor temperature and humidity
C) To serve as a primary heating source
D) To replace mechanical ventilation systems
Answer: B
Rationale: Under NAC 624.380, the C-21B subclassification
specifically covers equipment that uses evaporation,
,Page 2 of 164
refrigeration, boilers, or combustion for the control of air
temperatures, including humidity controls .
Q2. What is the term for heat that changes the temperature of
a substance without changing its physical state?
A) Latent heat
B) Superheat
C) Subcooling
D) Sensible heat
Answer: D
Rationale: Sensible heat is the energy added or removed that
causes a change in temperature. Latent heat causes a phase
change (melting, boiling) without a temperature change .
,Page 3 of 164
Q3. In the vapor-compression cycle, which component
absorbs heat from the conditioned space?
A) Compressor
B) Condenser
C) Expansion valve
D) Evaporator
Answer: D
Rationale: The evaporator allows low-pressure liquid refrigerant
to boil and turn into a gas, absorbing latent heat from the indoor
air passing over its coils .
Q4. What is the term "superheat" referring to in refrigeration?
A) The temperature of the refrigerant in the condenser
B) The temperature of the vapor refrigerant above its saturation
temperature
, Page 4 of 164
C) The temperature of the liquid refrigerant below its saturation
point
D) The outdoor ambient temperature plus the heat of
compression
Answer: B
Rationale: Superheat is the difference between the actual
temperature of the refrigerant vapor and its saturation
temperature (boiling point) at the same pressure. It ensures no
liquid enters the compressor .
Q5. Which component creates the pressure drop that allows
the refrigerant to expand and cool before entering the
evaporator?
A) Accumulator
B) Compressor
Nevada C-21B Air Conditioning Contractor
Practice Exam 2025/2026 Latest Questions
& Verified Answers | Instant PDF
Download
Q1. Which of the following best describes the primary
function of an air conditioning system as defined for a C-21B
contractor in Nevada?
A) To provide complete building automation
B) To regulate indoor temperature and humidity
C) To serve as a primary heating source
D) To replace mechanical ventilation systems
Answer: B
Rationale: Under NAC 624.380, the C-21B subclassification
specifically covers equipment that uses evaporation,
,Page 2 of 164
refrigeration, boilers, or combustion for the control of air
temperatures, including humidity controls .
Q2. What is the term for heat that changes the temperature of
a substance without changing its physical state?
A) Latent heat
B) Superheat
C) Subcooling
D) Sensible heat
Answer: D
Rationale: Sensible heat is the energy added or removed that
causes a change in temperature. Latent heat causes a phase
change (melting, boiling) without a temperature change .
,Page 3 of 164
Q3. In the vapor-compression cycle, which component
absorbs heat from the conditioned space?
A) Compressor
B) Condenser
C) Expansion valve
D) Evaporator
Answer: D
Rationale: The evaporator allows low-pressure liquid refrigerant
to boil and turn into a gas, absorbing latent heat from the indoor
air passing over its coils .
Q4. What is the term "superheat" referring to in refrigeration?
A) The temperature of the refrigerant in the condenser
B) The temperature of the vapor refrigerant above its saturation
temperature
, Page 4 of 164
C) The temperature of the liquid refrigerant below its saturation
point
D) The outdoor ambient temperature plus the heat of
compression
Answer: B
Rationale: Superheat is the difference between the actual
temperature of the refrigerant vapor and its saturation
temperature (boiling point) at the same pressure. It ensures no
liquid enters the compressor .
Q5. Which component creates the pressure drop that allows
the refrigerant to expand and cool before entering the
evaporator?
A) Accumulator
B) Compressor
