Refrigeration RT/RC Prep Quiz

Topics: All categories in the pool

1: On cooling towers, what causes the condenser water to drop

• tower fans
• ambient temperatures
• evaporation of the water droplets
• sensible heat

2: An oil pressure safety switch should be set at

• 5 to 10 psi below low side pressure
• 10 to 15 psi below low side pressure
• 10-15 psi above low side pressure
• 5 to 10 psi above low side pressure

3: A professional or office building would be considered what type of occupancy?

• mercantile
• commercial
• business
• public assembly

4: What type of material can't be used on the outlet of a relief valve?

• Copper
• Magnesium alloy
• Stainless steel
• PVC

5: Pressure-limiting device isn't required on a factory-sealed system containing less than ____ lbs.

• 50
• 33
• 18
• 22

6: What type of relief valve is used on low pressure centrifugal compressor systems?

• Spring-loaded relief valve
• Rupture disc
• Purge relief
• None of the above

7: A plug containing an alloy that will melt at a specific temperature to relief pressure is a

• relief plug
• fusion plug
• rupture plug
• fusible plug

8: A hotel is considered a _______ occupancy.

• residential
• commercial
• institutional
• mercantile

9: Which refrigerant is lighter than air?

• R-11
• R-134a
• R-123
• R-717

10: 1 Watt = ______ BTU's?

• 12
• 7.216
• 4.482
• 3.412

11: The maximum permissible amperage draw for a 40VA transfomer with a secondary voltage of 24V is

• .1
• 1.7
• .8
• 1.2

12: A halide torch is most useful with a freon compression system

• to remove from from TXV's and evaporator coils
• to detect refrigeration leaks in piping joints
• to sweat flanges on the refrigeration piping
• to release a sticking valve

13: The level of voltage caused by back electromagnetic force that opens the contacts of a potential relay in order to take the start capacitor out of the circuit is

• boost voltage
• lift voltage
• pick up voltage
• run voltage

14: Refrigerant restricted in 2004 but used for transition for decades:

• R-134A
• R-123
• R-22
• R-11

15: What is Absolute Zero?

• -400F
• -460F
• -773F
• -640F

16: Mercury was used in thermometers primarily because it

• was inexpensive
• expands uniformly
• never freezes
• vaporizes at very high temperatures

17: Brazed joints melt at temperatures above

• 1,000F
• 1,200F
• 500F
• 800F

18: On a large centrifugal system, what meters the flow to the evaporator?

• Cap tube.
• Low side float
• TXV
• High side float

19: At higher altitudes, the boiling point of refrigerant is

• the same
• higher
• equal to the coefficient of water at 32F
• lower

20: The main cause of enacting the "no vending rule" of July 1st 1992 was

• global warming potential
• ozone depletion
• both a & b
• None of the above

21: Sensible heat is the heat added to a substance to

• cause evaporation
• change its state
• freeze it
• raise its temperature

22: Booster compressors connect to the ____ side of the compressor

• oil side
• low side
• vapor
• liquid

23: Industrial occupancy is

• a premise or that portion of a premise that is not open to the public, where access by authorized persons is controlled, and that is used to manufacture, process, or store goods, such as chemicals, food, ice, meat, or petroleum.
• is a premise or that portion of a premise where large number of people congregate and from which occupants cannot quickly vacate the space.
• a premise or that portion of a premise where people transact business, receive personal service, or purchase food and other goods.
• Both a and b are correct

24: The total amount of refrigerant stored in a machinery room in all containers not provided with relief valves shall not exceed

• 550 lbs
• 330 lbs.
• 660 lbs
• 55 lbs

25: On a day with low relative humidity, the two thermometers on a sling psychrometer will read

• far apart or greater difference
• 2F difference
• nearly the same
• a ling psychrometer doesn't have two theremometers.