Q11-3. Heat added to a substance, which changes its
When the compressor is started, it draws refrigerant
temperature but NOT its physical state, is
gas from the evaporator. The gas is normally cool and
known as what type of heat?
under low pressure when it enters the compressor. In
the compressor, the gas is compressed (raises its
1.
Sensible heat
pressure) and, in the process, becomes hot. The hot,
2.
Specific heat
compressed gas leaves the discharge side of the
3.
Latent heat
compressor and flows to the condenser. The condenser,
4.
Total heat
which is surrounded by a cooling medium, such as air
Q11-4. During the conversion of a substance from
or water, dissipates some of the heat produced during
one physical state to another, heat absorbed
the compression process. Removing the heat also
or given up is known as what type of heat?
causes the gas to condense into a liquid, which is still
under high pressure. From the condenser, the liquid
1.
Sensible heat
refrigerant flows to the receiver, which acts as a
2.
Specific heat
reservoir.
3.
Latent heat
4.
Total heat
From the receiver, the liquid flows through the heat
exchanger, where cool gas moving from the evaporator
Q11-5. Heat that is added to a vapor to raise the
to the compressor dissipates more heat from the
temperature of the vapor is known as what
refrigerant. From the heat exchanger, the liquid travels
type of heat?
to a metering device, such as an expansion valve. At the
1.
Sensible heat
input side of the expansion valve, the liquid refrigerant
2.
Super heat
is under high pressure. The metering process of the
3.
Latent heat
expansion valve lowers the pressure and temperature of
4.
Total heat
the liquid refrigerant and feeds it to the evaporator.
Q11-6. Which of the following is NOT a type of heat
The low-pressure liquid passing through the
transfer?
evaporator absorbs heat, causing it to boil (evaporate)
and change back into a gas. This change, from liquid to
1.
Convention
gas, produces a cooling effect within the evaporator
2.
Conduction
coils, and the coils become cold. The air to be cooled is
3.
Absorption
then moved over the cold evaporator coils and directed
4.
into the space that is to be cooled. The gaseous
Q11-7. Which of the following laws states: "The
refrigerant, now cool and under low pressure, is drawn
volume of gas varies inversely to the pressure,
back to the compressor, where it is again compressed
provided the temperature remains constant?"
and started back through the cycle.
1.
Dalton's law
Q11-1. The quantity of heat possessed by a substance
2.
Charles' law
is measured in terms of which of the following
3.
Philip's law
measurements?
4.
Boyle's law
1.
Specific heat
Q11-8. Which of the following laws states: "At
2.
Latent heat
a constant pressure, the volume of a
3.
Heat absorption level
compressed gas varies directly to the absolute
4.
British thermal unit
temperature; at a constant volume, pres-
Q11-2. Heat added to a substance to raise the
sure varies directly to the absolute tem-
temperature 1 degree is known by which of the
perature"?
following terms?
1.
Dalton's law
1.
Sensible heat
2.
Charles' law
2.
Specific heat
3.
Philip's law
3.
Latent heat
4.
Boyle's law
4.
Total heat
11-8