Modern Refrigeration and Air Conditioning Chapter 8 EXAM 2025
QUESTIONS AND CORRECT ANSWER
Copper has a greater coefficient of __________ than steel. - answer>>>Expansion
The mercury switch is most often used on? - answer>>>Air conditioning and heating
thermostats
What are some advantages of electronic controls? - answer>>>Reliable, compact, rapid
response times, and lack of moving parts
Electrical power to the unit is obtained through an _________ _________ _______. -
answer>>>Insulated Electrical Cord
How does the current (magnetic) relay operate? - answer>>>uses the electrical characteristics
of the motor
Electrical Circuits contain what? - answer>>>A power source, a switch, and an electrical load
The magnetic relay is an electromagnet much like a _________ ________. - answer>>>Solenoid
valve
Current relays are sometimes called __________ ________ since it is the ampere draw on the
circuit that operates the relay. - answer>>>Amperage relays
_________ ______ (sometimes called voltage relays) are usually used with high torque,
capacitor-start motors. - answer>>>Potential relays
The electrical load is most often a _________. - answer>>>Motor
, Resistance of the relay coil to voltage must be high enough to prevent the contact points from
opening before the motor reaches __ to 90 percent of its full speed. - answer>>>80
Relays using solid-state transistors, diodes, silicon controlled rectifiers, diacs, and triacs are now
being used to _______ _________of hermetic motors. - answer>>>Control starting
___________ ________ relays are not as sensitive to the size of the motor as other relays. -
answer>>>Solid-State Electronic
In general, relays should be replaced, not __________. - answer>>>Repaired
The wire size, the contact point area, and the spring tension or weight plus the air gaps, must
be _________ _____ for each unit. - answer>>>Accurately set
If an exact potential relay replacement is not available use one of a _________ rating rather
than a higher voltage rating. - answer>>>Lower
Refrigerators with manual defrost frequently use a _________ ________ _____ control. -
answer>>>double capillary tube
When the coils are ___________, the defrost capillary tube will create enough bellows pressure
to open the defrost circuit and return the control connections to the motor circuit. -
answer>>>Defrosted
What does the hot gas defrost method do? - answer>>>uses a solenoid valve to open and close
the bypass from the compressor discharge to the evaporator.
What is the hot gas defrost method similar to? - answer>>>the solenoid valves used to control
refrigerant flow in secondary systems of two-temperature refrigerators.
QUESTIONS AND CORRECT ANSWER
Copper has a greater coefficient of __________ than steel. - answer>>>Expansion
The mercury switch is most often used on? - answer>>>Air conditioning and heating
thermostats
What are some advantages of electronic controls? - answer>>>Reliable, compact, rapid
response times, and lack of moving parts
Electrical power to the unit is obtained through an _________ _________ _______. -
answer>>>Insulated Electrical Cord
How does the current (magnetic) relay operate? - answer>>>uses the electrical characteristics
of the motor
Electrical Circuits contain what? - answer>>>A power source, a switch, and an electrical load
The magnetic relay is an electromagnet much like a _________ ________. - answer>>>Solenoid
valve
Current relays are sometimes called __________ ________ since it is the ampere draw on the
circuit that operates the relay. - answer>>>Amperage relays
_________ ______ (sometimes called voltage relays) are usually used with high torque,
capacitor-start motors. - answer>>>Potential relays
The electrical load is most often a _________. - answer>>>Motor
, Resistance of the relay coil to voltage must be high enough to prevent the contact points from
opening before the motor reaches __ to 90 percent of its full speed. - answer>>>80
Relays using solid-state transistors, diodes, silicon controlled rectifiers, diacs, and triacs are now
being used to _______ _________of hermetic motors. - answer>>>Control starting
___________ ________ relays are not as sensitive to the size of the motor as other relays. -
answer>>>Solid-State Electronic
In general, relays should be replaced, not __________. - answer>>>Repaired
The wire size, the contact point area, and the spring tension or weight plus the air gaps, must
be _________ _____ for each unit. - answer>>>Accurately set
If an exact potential relay replacement is not available use one of a _________ rating rather
than a higher voltage rating. - answer>>>Lower
Refrigerators with manual defrost frequently use a _________ ________ _____ control. -
answer>>>double capillary tube
When the coils are ___________, the defrost capillary tube will create enough bellows pressure
to open the defrost circuit and return the control connections to the motor circuit. -
answer>>>Defrosted
What does the hot gas defrost method do? - answer>>>uses a solenoid valve to open and close
the bypass from the compressor discharge to the evaporator.
What is the hot gas defrost method similar to? - answer>>>the solenoid valves used to control
refrigerant flow in secondary systems of two-temperature refrigerators.
