NEVADA C-21B AIR-CONDITIONING CONTRACTOR
EXAMINATION COMPLETE QUESTIONS AND
DETAILED SOLUTIONS LATEST UPDATE THIS YEAR
JUST RELEASED
1.
Which description most accurately identifies the type of work
authorized under Nevada's C-21B Air-Conditioning contractor
classification?
A. Installation and repair of only residential electrical wiring
B. Installation, repair, service, and maintenance of air-temperature-
control equipment and related ductwork
C. Fabrication of every type of structural steel component
D. Installation of underground municipal water distribution systems
Answer: B
Rationale: Nevada regulations identify C-21B as covering installation,
repair, service, and maintenance of equipment and related ductwork
used to control air temperatures, including associated humidity and
thermostatic controls. (
2.
Why is understanding the exact C-21B classification scope particularly
important before accepting an air-conditioning installation project in
Nevada?
,A. It determines whether the contractor's license authorizes the
proposed work
B. It determines which refrigerant color must be used
C. It eliminates all local permit requirements
D. It determines the customer's electricity provider
Answer: A
Rationale: A contractor should perform work only within the authority
of the applicable license classification, because Nevada requires
licensing appropriate to the scope of contracted work.
3.
In a conventional vapor-compression air-conditioning system, what
fundamental process allows heat to be removed from conditioned
indoor air?
A. Refrigerant absorbs heat in the evaporator and rejects it through the
condenser
B. Refrigerant creates coldness by eliminating atmospheric pressure
C. Compressor oil absorbs all indoor heat and permanently stores it
D. Condenser air is circulated directly through the occupied space
Answer: A
Rationale: The evaporator absorbs heat from indoor air while the
refrigerant changes state, and the condenser subsequently rejects that
absorbed heat outdoors.
,4.
Which component normally receives low-pressure refrigerant vapor
and increases its pressure and temperature before sending it toward
the condenser?
A. Evaporator coil
B. Compressor
C. Expansion valve
D. Filter-drier
Answer: B
Rationale: The compressor raises refrigerant vapor pressure and
temperature, producing the high-pressure discharge vapor required for
effective heat rejection.
5.
What is the primary purpose of the condenser coil in a conventional
vapor-compression air-conditioning system operating normally?
A. Absorb heat from indoor air
B. Reduce electrical voltage supplied to the compressor
C. Reject refrigerant heat to the surrounding environment
D. Meter liquid refrigerant into the evaporator
Answer: C
Rationale: The condenser removes heat from the high-pressure
refrigerant, allowing it to condense from vapor into high-pressure
liquid.
, 6.
Why does refrigerant undergo a pressure reduction when passing
through an expansion device before entering the evaporator?
A. The pressure reduction creates conditions allowing refrigerant to
evaporate at a lower temperature
B. The pressure reduction increases compressor horsepower
automatically
C. The pressure reduction removes moisture from the building
D. The pressure reduction converts all refrigerant immediately into
solid material
Answer: A
Rationale: Lowering refrigerant pressure reduces its saturation
temperature, allowing the refrigerant to absorb heat from indoor air
during evaporation.
7.
Which condition would most directly reduce an evaporator's ability to
transfer heat from indoor air into the refrigerant?
A. Proper airflow across a clean coil
B. A severely restricted evaporator coil with insufficient heat-transfer
surface exposed to airflow
C. Correct refrigerant charge and airflow
D. Normal blower operation at the manufacturer's specified airflow
EXAMINATION COMPLETE QUESTIONS AND
DETAILED SOLUTIONS LATEST UPDATE THIS YEAR
JUST RELEASED
1.
Which description most accurately identifies the type of work
authorized under Nevada's C-21B Air-Conditioning contractor
classification?
A. Installation and repair of only residential electrical wiring
B. Installation, repair, service, and maintenance of air-temperature-
control equipment and related ductwork
C. Fabrication of every type of structural steel component
D. Installation of underground municipal water distribution systems
Answer: B
Rationale: Nevada regulations identify C-21B as covering installation,
repair, service, and maintenance of equipment and related ductwork
used to control air temperatures, including associated humidity and
thermostatic controls. (
2.
Why is understanding the exact C-21B classification scope particularly
important before accepting an air-conditioning installation project in
Nevada?
,A. It determines whether the contractor's license authorizes the
proposed work
B. It determines which refrigerant color must be used
C. It eliminates all local permit requirements
D. It determines the customer's electricity provider
Answer: A
Rationale: A contractor should perform work only within the authority
of the applicable license classification, because Nevada requires
licensing appropriate to the scope of contracted work.
3.
In a conventional vapor-compression air-conditioning system, what
fundamental process allows heat to be removed from conditioned
indoor air?
A. Refrigerant absorbs heat in the evaporator and rejects it through the
condenser
B. Refrigerant creates coldness by eliminating atmospheric pressure
C. Compressor oil absorbs all indoor heat and permanently stores it
D. Condenser air is circulated directly through the occupied space
Answer: A
Rationale: The evaporator absorbs heat from indoor air while the
refrigerant changes state, and the condenser subsequently rejects that
absorbed heat outdoors.
,4.
Which component normally receives low-pressure refrigerant vapor
and increases its pressure and temperature before sending it toward
the condenser?
A. Evaporator coil
B. Compressor
C. Expansion valve
D. Filter-drier
Answer: B
Rationale: The compressor raises refrigerant vapor pressure and
temperature, producing the high-pressure discharge vapor required for
effective heat rejection.
5.
What is the primary purpose of the condenser coil in a conventional
vapor-compression air-conditioning system operating normally?
A. Absorb heat from indoor air
B. Reduce electrical voltage supplied to the compressor
C. Reject refrigerant heat to the surrounding environment
D. Meter liquid refrigerant into the evaporator
Answer: C
Rationale: The condenser removes heat from the high-pressure
refrigerant, allowing it to condense from vapor into high-pressure
liquid.
, 6.
Why does refrigerant undergo a pressure reduction when passing
through an expansion device before entering the evaporator?
A. The pressure reduction creates conditions allowing refrigerant to
evaporate at a lower temperature
B. The pressure reduction increases compressor horsepower
automatically
C. The pressure reduction removes moisture from the building
D. The pressure reduction converts all refrigerant immediately into
solid material
Answer: A
Rationale: Lowering refrigerant pressure reduces its saturation
temperature, allowing the refrigerant to absorb heat from indoor air
during evaporation.
7.
Which condition would most directly reduce an evaporator's ability to
transfer heat from indoor air into the refrigerant?
A. Proper airflow across a clean coil
B. A severely restricted evaporator coil with insufficient heat-transfer
surface exposed to airflow
C. Correct refrigerant charge and airflow
D. Normal blower operation at the manufacturer's specified airflow
