REFRIGERATION AND AIR CONDITIONING

1.Short cycling of a refrigeration compressor refers to _____________.

A.frequently grounding out

B.frequently starting and stopping

C.running too fast

D.running too slow

[bg_collapse view=”button-orange” color=”#49494a” expand_text=”View Answer” collapse_text=”Hide Answer” ]B.frequently starting and stopping[/bg_collapse]

2.The heat gained per pound of refrigerant in the evaporator is known as the _____________.

A.latent heat of vaporization

B.sensible heat

C.refrigerating effect

D.specific heat of vaporization

[bg_collapse view=”button-orange” color=”#49494a” expand_text=”View Answer” collapse_text=”Hide Answer” ]C.refrigerating effect[/bg_collapse]

3.When liquid reaches the compressor of a refrigeration system through the suction line, the condition is called _____________.

A.flooding back

B.superheating

C.overflowing

D.recycling

[bg_collapse view=”button-orange” color=”#49494a” expand_text=”View Answer” collapse_text=”Hide Answer” ]A.flooding back[/bg_collapse]

4.Which of the refrigerants listed is considered safe and ideal for most marine applications?

A.R-21

B.Ammonia

C.R-12

D.Sulfur dioxide

[bg_collapse view=”button-orange” color=”#49494a” expand_text=”View Answer” collapse_text=”Hide Answer” ]C.R-12[/bg_collapse]

5.The heat removed from the refrigerant in the condenser of a refrigeration plant is the _____________.

A.latent heat of expansion

B.sensible heat of condensation

C.heat of compression

D.all of the above

[bg_collapse view=”button-orange” color=”#49494a” expand_text=”View Answer” collapse_text=”Hide Answer” ]C.heat of compression[/bg_collapse]

6.The FIRST thing to do to ensure that a refrigeration unit will not start while undergoing repairs, is to ____________.

A.secure and tag the electrical circuit

B.place a crow bar in the flywheel of the unit

C.inform all persons in the area not to start the unit

D.make a log book entry

[bg_collapse view=”button-orange” color=”#49494a” expand_text=”View Answer” collapse_text=”Hide Answer” ]A.secure and tag the electrical circuit[/bg_collapse]

7.In a refrigeration system, the refrigerant absorbs the latent heat of vaporization in the _____________.
A.compressor

B.condenser

C.receiver

D.evaporator
[bg_collapse view=”button-orange” color=”#49494a” expand_text=”View Answer” collapse_text=”Hide Answer” ]D.evaporator[/bg_collapse]
8.Personnel working with refrigeration systems, and subject to the exposure of refgerants should wear ________________.

A.face shield

B.a respirator

C.rubber gloves

D.an all purpose gas mask
[bg_collapse view=”button-orange” color=”#49494a” expand_text=”View Answer” collapse_text=”Hide Answer” ]A.face shield[/bg_collapse]
9.The heat required to change a substance from a solid to a liquid while at its freezing temperature, is known as the latent heat of _____________.
A.fusion

B.vaporization

C.condensation

D.sublimation

[bg_collapse view=”button-orange” color=”#49494a” expand_text=”View Answer” collapse_text=”Hide Answer” ] A.fusion[/bg_collapse]
10.The only means of removing the latent heat of condensation from a refrigerant in the normal refrigeration cycle is by _________.

A.passing it through the expansion valve

B.condensing refrigerant in the system condenser

C.passing the gaseous refrigerant through the heat interchanger on the suction side of the compressor

D.maintaining a high pressure on the system’s receiver

[bg_collapse view=”button-orange” color=”#49494a” expand_text=”View Answer” collapse_text=”Hide Answer” ]B.condensing refrigerant in the system condenser[/bg_collapse]
11.The amount of moisture in a given sample of air, when compared with the amount of moisture the air could hold if totally saturated at the existing temperature of the sample, is called ____________.

A.absolute humidity

B.specific humidity

C.effective humidity

D.relative humidity

[bg_collapse view=”button-orange” color=”#49494a” expand_text=”View Answer” collapse_text=”Hide Answer” ]D.relative humidity[/bg_collapse]

12.When it is necessary to open a refrigeration system for repairs and the system will be open for more than a few minutes, the open ends of the system should be ____________.

A.dehydrated

B.purged

C.plugged

D.evacuated

[bg_collapse view=”button-orange” color=”#49494a” expand_text=”View Answer” collapse_text=”Hide Answer” ]C.plugged[/bg_collapse]
13.People familiar with ammonia refrigeration systems become accustomed to its odor and may forget that the vapors _____________.

A.in a low concentration can cause death

B.will dissolve in perspiration and cause caustic burns

C.will burn or explode

D.all of the above

[bg_collapse view=”button-orange” color=”#49494a” expand_text=”View Answer” collapse_text=”Hide Answer” ]D.all of the above[/bg_collapse]
14.When subjected to high heat from a open flame, or an electric heating element, which of the listed refrigerants will break down and produce phosgene gas?

A.CO2

B.Methyl chloride

C.R-22

D.Sulphur dioxide

[bg_collapse view=”button-orange” color=”#49494a” expand_text=”View Answer” collapse_text=”Hide Answer” ]C.R-22[/bg_collapse]
15.A refrigeration system contaminated with moisture can be affected by _____________.
A.acid formation

B.sludge formation

C.ice in the expansion valve

C.allowed to mix with compressor oil

[bg_collapse view=”button-orange” color=”#49494a” expand_text=”View Answer” collapse_text=”Hide Answer” ][/bg_collapse]

16.Some chloronated flourocarbon refrigerants may decompose into a toxic irritating gas if it is ____________.

A.stored at temperatures below 60 degrees Fahrenheit

B.charged into a system having copper fittings

D.all of the above

D.exposed to an open flame or hot surface

[bg_collapse view=”button-orange” color=”#49494a” expand_text=”View Answer” collapse_text=”Hide Answer” ]D.exposed to an open flame or hot surface[/bg_collapse]
17.In a direct expansion type cargo refrigeration system, a box is normally changed from chill to freeze by adjusting the _____________.

A.hand expansion valve
B.compressor suction valve

C.solenoid bypass

D.back pressure regulating valve

[bg_collapse view=”button-orange” color=”#49494a” expand_text=”View Answer” collapse_text=”Hide Answer” ]
D.back pressure regulating valve[/bg_collapse]
18.If the suction line between the evaporator and compressor is frosting up, the cause may be due to the thermal expansion valve _____________.

A.thermal bulb coming loose from the suction line

B.needle valve is stuck closed

C.thermal bulb is in a cold air stream

D.all of the above

[bg_collapse view=”button-orange” color=”#49494a” expand_text=”View Answer” collapse_text=”Hide Answer” ]A.thermal bulb coming loose from the suction line[/bg_collapse]

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