Michigan Mechanical Journeyman
Examination Questions and Correct Answers
(Verified Answers) Plus Rationale 2027 Q&A|
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1. What is the primary purpose of a mechanical ventilation system?
A. To increase building humidity
B. To eliminate the need for insulation
C. To provide controlled movement and replacement of air
D. To increase water pressure
Answer: C. To provide controlled movement and replacement of air
Rationale: Mechanical ventilation introduces, distributes, and/or
exhausts air to maintain acceptable indoor air quality and support
proper building conditions. It is not a substitute for insulation or a
water-pressure system.
2. Which component is primarily responsible for transferring heat
from refrigerant to surrounding air in an air-conditioning system?
,A. Evaporator
B. Condenser
C. Expansion valve
D. Compressor
Answer: B. Condenser
Rationale: The condenser rejects heat from the refrigerant to the
surrounding environment. As the refrigerant releases heat, it changes
from a high-pressure vapor toward a liquid state.
3. What is the primary function of a compressor in a refrigeration
system?
A. Reduce refrigerant pressure
B. Remove moisture from ductwork
C. Raise refrigerant pressure and circulate refrigerant
D. Regulate water temperature
Answer: C. Raise refrigerant pressure and circulate refrigerant
Rationale: The compressor takes low-pressure refrigerant vapor from
the evaporator and compresses it into a high-pressure vapor. This
pressure difference allows refrigerant to circulate through the system.
4. In a hydronic heating system, what medium commonly carries heat
throughout the building?
,A. Water
B. Compressed air only
C. Natural gas
D. Refrigerant vapor only
Answer: A. Water
Rationale: Hydronic systems use heated water, and in some systems
glycol solutions, to transfer thermal energy through piping to
radiators, baseboards, coils, or other heat emitters.
5. What is the primary purpose of an expansion tank in a closed
hydronic system?
A. Increase burner capacity
B. Absorb thermal expansion of the fluid
C. Remove combustion gases
D. Increase refrigerant pressure
Answer: B. Absorb thermal expansion of the fluid
Rationale: As water is heated, it expands. In a closed hydronic system,
an expansion tank provides a compressible volume that
accommodates this expansion and helps control system pressure.
6. What instrument is commonly used to measure static pressure in
an HVAC duct system?
, A. Manometer
B. Thermocouple only
C. Megohmmeter
D. Tachometer
Answer: A. Manometer
Rationale: A manometer can measure pressure differences in inches of
water column, a common unit for HVAC duct and air-system pressure
measurements.
7. What is the main purpose of duct insulation?
A. Increase air leakage
B. Reduce heat transfer and condensation
C. Increase static pressure
D. Eliminate the need for balancing
Answer: B. Reduce heat transfer and condensation
Rationale: Proper duct insulation reduces unwanted heat gain or loss
and can prevent condensation on surfaces carrying conditioned air.
8. Which device is commonly used to control airflow through a duct?
A. Damper
B. Trap primer
Examination Questions and Correct Answers
(Verified Answers) Plus Rationale 2027 Q&A|
Instant Download Pdf
1. What is the primary purpose of a mechanical ventilation system?
A. To increase building humidity
B. To eliminate the need for insulation
C. To provide controlled movement and replacement of air
D. To increase water pressure
Answer: C. To provide controlled movement and replacement of air
Rationale: Mechanical ventilation introduces, distributes, and/or
exhausts air to maintain acceptable indoor air quality and support
proper building conditions. It is not a substitute for insulation or a
water-pressure system.
2. Which component is primarily responsible for transferring heat
from refrigerant to surrounding air in an air-conditioning system?
,A. Evaporator
B. Condenser
C. Expansion valve
D. Compressor
Answer: B. Condenser
Rationale: The condenser rejects heat from the refrigerant to the
surrounding environment. As the refrigerant releases heat, it changes
from a high-pressure vapor toward a liquid state.
3. What is the primary function of a compressor in a refrigeration
system?
A. Reduce refrigerant pressure
B. Remove moisture from ductwork
C. Raise refrigerant pressure and circulate refrigerant
D. Regulate water temperature
Answer: C. Raise refrigerant pressure and circulate refrigerant
Rationale: The compressor takes low-pressure refrigerant vapor from
the evaporator and compresses it into a high-pressure vapor. This
pressure difference allows refrigerant to circulate through the system.
4. In a hydronic heating system, what medium commonly carries heat
throughout the building?
,A. Water
B. Compressed air only
C. Natural gas
D. Refrigerant vapor only
Answer: A. Water
Rationale: Hydronic systems use heated water, and in some systems
glycol solutions, to transfer thermal energy through piping to
radiators, baseboards, coils, or other heat emitters.
5. What is the primary purpose of an expansion tank in a closed
hydronic system?
A. Increase burner capacity
B. Absorb thermal expansion of the fluid
C. Remove combustion gases
D. Increase refrigerant pressure
Answer: B. Absorb thermal expansion of the fluid
Rationale: As water is heated, it expands. In a closed hydronic system,
an expansion tank provides a compressible volume that
accommodates this expansion and helps control system pressure.
6. What instrument is commonly used to measure static pressure in
an HVAC duct system?
, A. Manometer
B. Thermocouple only
C. Megohmmeter
D. Tachometer
Answer: A. Manometer
Rationale: A manometer can measure pressure differences in inches of
water column, a common unit for HVAC duct and air-system pressure
measurements.
7. What is the main purpose of duct insulation?
A. Increase air leakage
B. Reduce heat transfer and condensation
C. Increase static pressure
D. Eliminate the need for balancing
Answer: B. Reduce heat transfer and condensation
Rationale: Proper duct insulation reduces unwanted heat gain or loss
and can prevent condensation on surfaces carrying conditioned air.
8. Which device is commonly used to control airflow through a duct?
A. Damper
B. Trap primer
