Air Conditioning Certification Exam
(Exam Code A-02) Questions And
Answers
Heat which causes a change in temperature of a substance is called; - ANS sensible heat.
Heat which causes a change in state of a material without a change in temperature is called; -
ANS latent heat.
Heat which is added to a vapor after the change of state occurs is called; - ANS superheat.
Heat can travel by; - ANS conduction, convection, radiation.
The movement of heat by way of fluid (or air) is called; - ANS convection .
The movement of heat by direct contact is called; - ANS conduction .
The standard unit for measuring the quantity of heat in a substance is; - ANS the British
Thermal Unit (Btu).
A refrigerat gives up heat when; - ANS it condenses.
It is desirable for refrigerant in the suction line to be slightly superheated in order to; - ANS
insure liquid refrigerant does not enter the compressor.
The state of refrigerant in the suction line should be; - ANS low pressure/ low temperature.
The state of the refrigerant entering the condenser is; - ANS high pressure/ highly
superheated liquid.
The evaporator; - ANS Transfers heat from the refrigerant to the ambient air.
Which of the following is NOT a thermodynamic property of refrigerants?
a) Critical point.
b) Saturation point.
c) Enthalpy.
d) Flammability. - ANS d) Flammability.
, The sequential order of steps in the vapor - compression process are; - ANS compression,
condensation, expansion, vaporization.
If a 30 pound cylinder of reclaimed R-12 refrigerant has been stored over night at 70°F, the
pressure in the cylinder should be approximately; - ANS 70.2 Psig.
Pressures lower than atmospheric are measured in;
a) inches of mercury
b) microns
c) Psig
d) either "A" or "B". - ANS d) either "A" or "B".
Zero psia (pounds per square inch absolute) is; - ANS a pressure which cannot be further
reduced.
Zero psig (pounds per square inch guage) is; - ANS the same as atmospheric pressure.
The temperature at which moisture will start to condense from the air is called; - ANS dew
point temperature.
A compound pressure guage measures; - ANS pressure and vacuum.
A mechanical shaft seal is necessary on a; - ANS open drive compressor.
Liquid slugging is; - ANS liquid refrigerant in the compressor clearance space.
The clearance space in a reciprocating compressor; - ANS has an effect on compressor
capacity.
Which of the following will cause a change in compressor capacity?
a) suction pressure.
b) discharge pressure.
c) refrigerant vapor density.
d) all of the above. - ANS d) all of the above
The main function of the condenser is to; - ANS remove heat from the refrigerant.
Refrigerant R12 vapor enters the condenser at 116.9 psig, 100 F. It leaves the condenser at 80
F. Its pressure will be approximately; - ANS 84.1 psig.
There are three basic types of condensers, the air cooled, the water cooled and the
__________cooled. - ANS evaporative.
(Exam Code A-02) Questions And
Answers
Heat which causes a change in temperature of a substance is called; - ANS sensible heat.
Heat which causes a change in state of a material without a change in temperature is called; -
ANS latent heat.
Heat which is added to a vapor after the change of state occurs is called; - ANS superheat.
Heat can travel by; - ANS conduction, convection, radiation.
The movement of heat by way of fluid (or air) is called; - ANS convection .
The movement of heat by direct contact is called; - ANS conduction .
The standard unit for measuring the quantity of heat in a substance is; - ANS the British
Thermal Unit (Btu).
A refrigerat gives up heat when; - ANS it condenses.
It is desirable for refrigerant in the suction line to be slightly superheated in order to; - ANS
insure liquid refrigerant does not enter the compressor.
The state of refrigerant in the suction line should be; - ANS low pressure/ low temperature.
The state of the refrigerant entering the condenser is; - ANS high pressure/ highly
superheated liquid.
The evaporator; - ANS Transfers heat from the refrigerant to the ambient air.
Which of the following is NOT a thermodynamic property of refrigerants?
a) Critical point.
b) Saturation point.
c) Enthalpy.
d) Flammability. - ANS d) Flammability.
, The sequential order of steps in the vapor - compression process are; - ANS compression,
condensation, expansion, vaporization.
If a 30 pound cylinder of reclaimed R-12 refrigerant has been stored over night at 70°F, the
pressure in the cylinder should be approximately; - ANS 70.2 Psig.
Pressures lower than atmospheric are measured in;
a) inches of mercury
b) microns
c) Psig
d) either "A" or "B". - ANS d) either "A" or "B".
Zero psia (pounds per square inch absolute) is; - ANS a pressure which cannot be further
reduced.
Zero psig (pounds per square inch guage) is; - ANS the same as atmospheric pressure.
The temperature at which moisture will start to condense from the air is called; - ANS dew
point temperature.
A compound pressure guage measures; - ANS pressure and vacuum.
A mechanical shaft seal is necessary on a; - ANS open drive compressor.
Liquid slugging is; - ANS liquid refrigerant in the compressor clearance space.
The clearance space in a reciprocating compressor; - ANS has an effect on compressor
capacity.
Which of the following will cause a change in compressor capacity?
a) suction pressure.
b) discharge pressure.
c) refrigerant vapor density.
d) all of the above. - ANS d) all of the above
The main function of the condenser is to; - ANS remove heat from the refrigerant.
Refrigerant R12 vapor enters the condenser at 116.9 psig, 100 F. It leaves the condenser at 80
F. Its pressure will be approximately; - ANS 84.1 psig.
There are three basic types of condensers, the air cooled, the water cooled and the
__________cooled. - ANS evaporative.
