Nevada (NV) C-21B Air Conditioning Contractor Practice
Exam 2026 – 200 Questions with Answers & Explanations |
INSTANT PDF DOWNLOAD
Coverage:
This Nevada (NV) C-21B Air Conditioning Contractor Practice Exam covers all key
areas required for the state licensing test, including HVAC system fundamentals,
refrigeration principles, heat pumps, air distribution, electrical controls, safety
protocols, load calculations, refrigerant handling, troubleshooting, and code
compliance (IMC & NEC). Includes 200 multiple-choice questions with detailed
answers and explanations to help candidates prepare for the 2026 licensing exam.
Q1. The primary function of an air conditioning system is to:
A. Add heat to indoor air
B. Remove heat and moisture from indoor air
C. Increase air pressure
D. Eliminate outdoor air infiltration
Answer: B
Air conditioning works by removing heat and humidity from indoor spaces to
improve comfort.
Q2. Which component of the refrigeration cycle raises the pressure and
temperature of the refrigerant?
A. Condenser
B. Evaporator
C. Expansion valve
D. Compressor
Answer: D
The compressor compresses low-pressure vapor into high-pressure, high-
temperature vapor.
,Q3. What type of refrigerant change occurs in the evaporator coil?
A. Liquid to liquid
B. Vapor to liquid
C. Liquid to vapor
D. Vapor to vapor
Answer: C
The refrigerant absorbs heat and boils into a vapor inside the evaporator.
Q4. High superheat readings usually indicate:
A. Overcharged system
B. Low refrigerant charge or restricted airflow
C. Faulty condenser fan
D. Excessive subcooling
Answer: B
High superheat means insufficient refrigerant or poor heat absorption.
Q5. Which device controls the amount of refrigerant entering the evaporator?
A. Compressor
B. Condenser fan
C. Metering device
D. Receiver
Answer: C
Metering devices regulate refrigerant flow and pressure drop.
Q6. Which motor is most commonly used in residential AC condensers?
,A. DC motor
B. Stepper motor
C. Single-phase induction motor
D. Synchronous motor
Answer: C
Residential systems typically use single-phase induction motors.
Q7. What electrical component provides the initial torque to start a compressor
motor?
A. Contactor
B. Start capacitor
C. Transformer
D. Relay
Answer: B
Start capacitors provide a temporary boost to motor starting torque.
Q8. Which voltage reading indicates a normal 240V circuit?
A. 110–115V
B. 208V
C. 230–250V
D. 277V
Answer: C
Residential 240V systems typically operate within this voltage range.
Q9. The purpose of subcooling is to ensure:
A. Vapor leaves the condenser
B. Only liquid refrigerant reaches the metering device
, C. Lower suction pressure
D. Faster evaporation
Answer: B
Subcooling prevents flash gas before the metering device.
Q10. What condition causes high head pressure?
A. Dirty evaporator coil
B. Low refrigerant charge
C. Dirty condenser coil
D. Low ambient temperature
Answer: C
Restricted heat rejection increases head pressure.
Q11. Which safety device opens when excessive pressure is detected?
A. Thermostat
B. Contactor
C. High-pressure switch
D. Transformer
Answer: C
High-pressure switches protect the system from damage.
Q12. Which refrigerant is being phased out due to ozone depletion?
A. R-410A
B. R-134a
C. R-22
D. R-32
Exam 2026 – 200 Questions with Answers & Explanations |
INSTANT PDF DOWNLOAD
Coverage:
This Nevada (NV) C-21B Air Conditioning Contractor Practice Exam covers all key
areas required for the state licensing test, including HVAC system fundamentals,
refrigeration principles, heat pumps, air distribution, electrical controls, safety
protocols, load calculations, refrigerant handling, troubleshooting, and code
compliance (IMC & NEC). Includes 200 multiple-choice questions with detailed
answers and explanations to help candidates prepare for the 2026 licensing exam.
Q1. The primary function of an air conditioning system is to:
A. Add heat to indoor air
B. Remove heat and moisture from indoor air
C. Increase air pressure
D. Eliminate outdoor air infiltration
Answer: B
Air conditioning works by removing heat and humidity from indoor spaces to
improve comfort.
Q2. Which component of the refrigeration cycle raises the pressure and
temperature of the refrigerant?
A. Condenser
B. Evaporator
C. Expansion valve
D. Compressor
Answer: D
The compressor compresses low-pressure vapor into high-pressure, high-
temperature vapor.
,Q3. What type of refrigerant change occurs in the evaporator coil?
A. Liquid to liquid
B. Vapor to liquid
C. Liquid to vapor
D. Vapor to vapor
Answer: C
The refrigerant absorbs heat and boils into a vapor inside the evaporator.
Q4. High superheat readings usually indicate:
A. Overcharged system
B. Low refrigerant charge or restricted airflow
C. Faulty condenser fan
D. Excessive subcooling
Answer: B
High superheat means insufficient refrigerant or poor heat absorption.
Q5. Which device controls the amount of refrigerant entering the evaporator?
A. Compressor
B. Condenser fan
C. Metering device
D. Receiver
Answer: C
Metering devices regulate refrigerant flow and pressure drop.
Q6. Which motor is most commonly used in residential AC condensers?
,A. DC motor
B. Stepper motor
C. Single-phase induction motor
D. Synchronous motor
Answer: C
Residential systems typically use single-phase induction motors.
Q7. What electrical component provides the initial torque to start a compressor
motor?
A. Contactor
B. Start capacitor
C. Transformer
D. Relay
Answer: B
Start capacitors provide a temporary boost to motor starting torque.
Q8. Which voltage reading indicates a normal 240V circuit?
A. 110–115V
B. 208V
C. 230–250V
D. 277V
Answer: C
Residential 240V systems typically operate within this voltage range.
Q9. The purpose of subcooling is to ensure:
A. Vapor leaves the condenser
B. Only liquid refrigerant reaches the metering device
, C. Lower suction pressure
D. Faster evaporation
Answer: B
Subcooling prevents flash gas before the metering device.
Q10. What condition causes high head pressure?
A. Dirty evaporator coil
B. Low refrigerant charge
C. Dirty condenser coil
D. Low ambient temperature
Answer: C
Restricted heat rejection increases head pressure.
Q11. Which safety device opens when excessive pressure is detected?
A. Thermostat
B. Contactor
C. High-pressure switch
D. Transformer
Answer: C
High-pressure switches protect the system from damage.
Q12. Which refrigerant is being phased out due to ozone depletion?
A. R-410A
B. R-134a
C. R-22
D. R-32
