Multiple Choice
Identify the
choice that best completes the statement or answers the question.
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1.
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The evaporator temperature has
to be lower than the box temperature because:
a. | Heat goes to cold; the heat in the
box must transfer to the refrigerant in the evaporator.
| b. | The compressor will be damaged by too high a suction
temperature.
| c. | Expansion valves are designed to lower evaporator
temperatures |
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2.
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The condensing temperature has
to be higher than the ambient air temperature because:
a. | Heat goes to cold; the heat in the
condenser must transfer to the ambient air. | b. | The compressor is designed to only raise temperatures,
not lower them. | c. | To allow for a safety factor in case the condenser gets
dirty |
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3.
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f the R22 evaporator
temperature is 25°, what is its suction pressure supposed to be?
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4.
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The “high side” of
a refrigeration system is:
a. | Between the discharge of the
compressor and the inlet of the metering device. | b. | Between the outlet of the metering device and the inlet of
the compressor. | c. | The pressures inside the crankcase of the
compressor. |
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5.
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The difference between the
evaporator temperature and the suction line temperature at the coil outlet
is:
a. | superheat | b. | latent heat | c. | artificial heat | d. | extended heat |
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6.
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The condenser is designed
to:
a. | absorb
heat | b. | reject heat | c. | vaporize refrigerant | d. | warm the
space |
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7.
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6- How is subcooling determined? a. | Subtract the temperature of the
liquid line leaving the condenser from the condensing temperature | b. | Add the temperature of the vapor line leaving the
evaporator to the evaporator temperature | c. | Look at the high side gauge and find the temperature corresponding to the head
pressure. | d. | Look it up in the Yellow Pages |
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8.
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6- How can
you be sure a condenser is clean?
a.
b.
c.
a. | Hire good apprentices to clean the
units. | b. | Clean it yourself. | c. | Check the head
pressure. |
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9.
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6- What is the difference between slugging and flooding?
a. | Slugging is a little too much
refrigerant; flooding is way too much refrigerant | b. | Flooding is a little too much refrigerant; slugging is way
too much refrigerant | c. | No difference they are the same |
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10.
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6- How do you prevent flooding and
slugging? a. | Keep suction pressure
up. | b. | Keep superheat at proper levels. | c. | Install a crankcase heater or pump-down
solenoid. |
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