1. Which type of heat causes a change in temperature of a substance?
Answer:
a) Latent heat
b) Sensible heat
c) Superheat
d) Regular heat
2. Which type of heat causes a change in the state of a substance without a change in temperature?
Answer:
a) Latent heat
b) Sensible heat
c) Superheat
d) Regular heat
3. Which of the following are the stages, in order, for the refrigeration process that takes place in a condenser?
Answer:
a) Latent heat removal, de-superheating, sub-cooling
b) Addition of sensible heat, de-superheating, sub-cooling
c) De-superheating, latent heat removal, sub-cooling
d) Latent heat removal, sub-cooling, de-superheating
4. Most of the heat absorbed by the evaporator is due to refrigerant ____________.
Answer:
a) latent heat of vaporization
b) sub-cooling effect
c)superheated flash gas
d) sensible heat of vaporization
5. Why is it desirable for refrigerant entering the compressor to be slightly superheated?
Answer:
a) To prevent refrigerant oil from leaving the compressor
b) To prevent vapor refrigerant from entering the compressor
c) To keep the compressor warm
d) To prevent liquid refrigerant from entering the compressor
6. What is one effect of a refrigeration system that has a low refrigerant charge?
Answer:
a) High discharge line temperature
b) Increased condenser sub-cooling
c) Decrease in suction superheat
d) Increase in refrigerant flow velocity
7. What is done to increase the latent capacity of a central air conditioning system??
Answer:
a) Increase the evaporator’s refrigerant temperate
b) Operate the evaporator blower at a lower speed
c) Operate the evaporator blower at a higher speed
d) Use a higher rated evaporator coil compared to the condensing unit
8. What does a temperature differential across a filter-drier indicate?
Answer:
a) Normal operation
b) Refrigerant overcharge
c) Restricted filter-drier
d) Refrigerant undercharge
9. A compressor is operating with a discharge pressure of 416.3 psig and a suction pressure of 130.3 psig. What is the compression ratio (pumping ratio)?
10. What effect would a TEV have on an air conditioning system, if the TEV sensing bulb lost all of its charge?
Answer:
a) It would cause the high side pressure to increase to an unsafe limit.
b) The low side pressure would increase.
c) It would cause the oil pressure to decrease.
d) The low side pressure would decrease.
Copyright ©2024. All Rights Reserved BNP Media.
Design, CMS, Hosting & Web Development :: ePublishing