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In the refrigeration compressor the temperature of the vapor is （） by compression.
A . raised
B . risen
C . reduced
D . maintained constant
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The receiver used in a refrigeration system（）
A . stores liquid refrigerant
B . collects non-condensable gases
C . allows refrigerant sub-cooling
D . prevents compressor surging
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In a refrigeration system, if the cooling water to the condenser fails, the（）.
A . box temperature solenoid valve will close
B . expansion valve will close
C . compressor will shutdown
D . king valve will ope
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The temperature of the refrigerant in the evaporator coil depends mostly upon the （）.
A . refrigerant pressure in the evaporator
B . cooling water temperature to the condenser
C . heat load in the refrigerator compartment
D . solenoid valve in the liquid line
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In the refrigeration system, a shortage of refrigerant is indicated by （）.
A . the compressor short cycling on high pressure cut out switch
B . high suction pressure
C . high head pressure
D . bubbles in the sight gla
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In a refrigeration system, the refrigerant absorbs the latent heat of vaporization in the（）.
A . compressor
B . condenser
C . receiver
D . evaporator
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Excessive oil foaming in the crankcase of a refrigeration compressor can result in （）.
A . overheated compressor bearings
B . excess lube oil viscosity
C . carbon deposits on the compressor piston rings
D . wax crystals forming in the lubricant
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In a refrigeration system, foaming of the crankcase oil may cause the （）.
A . expansion valve to overfeed
B . compressor to knock
C . water regulating valve to fail
D . crankcase drains to plug
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In terms of pressure and temperature in the refrigerant in the compressor, what happens to the primary?（）
A . its pressure and temperature are both lowered
B . its pressure and temperature are both raised
C . its pressure is lowered and its temperature is raised
D . its pressure is raised and its temperature is lowered
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Refrigerant entering the compressor of a refrigeration system should be in which of the following conditions?（）
A . Sub-cooled liquid
B . Sub-cooled vapor
C . Superheated vapor
D . Liquid
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Moisture in the refrigerant may （）.
A . freeze on the expansion valve seat and reduce the flow of liquid refrigerant
B . emulsify the oil in the condenser
C . freeze in the king valve
D . clog the oil tra
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In a compression refrigeration plant the refrigerant is under low pressure in the （） and under high pressure in the （）.
A . compressor；condenser
B . condenser；evaporator
C . throttle valve；evaporator
D . evaporator；condenser
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Zinc rods are installed in the refrigeration system （）.
A . liquid strainer
B . liquid receiver
C . saltwater condenser
D . evaporator
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The presence of bubbles in a refrigeration system liquid line may （）.
A . promote refrigerant dehydration
B . be absorbed in the receiver
C . cause low condensing pressure
D . carry moisture and lead to corrosio
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The component of a refrigerating system in which the refrigerant vaporizes and absorbs heat is known as the （）.
A . condenser
B . vapor generator
C . accumulator
D . evaporator
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In which of the listed refrigeration system components does superheating of the refrigerant take place?（）
A . Expansion valve
B . Evaporator
C . Drier
D . Receiver
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In a compression refrigeration cycle, the temperature of the liquid refrigerant experiences its greatest decrease in the（）.
A . evaporator
B . compressor
C . expansion valve
D . condenser
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In a chilled water air conditioning unit using a reciprocating compressor, the refrigerating effect of the primary refrigerant can be increased by （）.
A . increasing refrigerant pressure in the coil
B . increasing chilled water flow through the cooler
C . sub-cooling the refrigerant in the condenser
D . superheating the refrigerant in the compressor
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If a refrigeration compressor is running continuously without lowering temperature as normal in the refrigerator, the trouble may be （）.
A . excessive condenser cooling water
B . warm food in the refrigerator
C . a shortage of refrigerant
D . s shortage of compressor oil
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The latent heat of evaporation is dissipated in the （） in a compression refrigeration system.
A . evaporator
B . condenser
C . expansion valve
D . compressor
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The function of （） in a refrigeration plant using Freon is to move moisture from all refrigeration system.
A . filter
B . filter drier
C . heat exchanger
D . air cooler
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If liquid refrigerant accidentally comes in contact with the eyes, （） immediately.
A . rub the eyes
B . irritate the eyes
C . wash the eyes with a heavy boric acid solution
D . obtain medical hel
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When a refrigeration compressor is in the ‘off’ cycle, the thermal expansion valve will（）.
A . always be wide open when the compressor restarts
B . continue to operate as if the system were in operation
C . remain open until evaporator pressure equalizes, then close until the compressor restarts
D . always be completely closed until the compressor restart
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When a refrigeration compressor is in the ‘off’ cycle, the thermal expansion valve will .
A.always be wide open when the compressor restarts
B.continue to operate as if the system were in operation
C.remain open until evaporator pressure equalizes, then close until the compressor restarts
D.always be completely closed until the compressor restarts
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Excessive circulation of the lubricating oil with the refrigerant in a refrigeration system will cause______.
A.carbon deposits on the compressor suction valves
B.the evaporator temperature to increase
C.rapid corrosion of the thermal expansion valve
D.no operating problems
