Topics: All categories in the pool
1: Who is permitted to access a refrigeration machine room?
- Anyone, it's a completely safe area
- Authorized persons only
- Any employee
- Contractors only
2: Heat that changes the physical state of a substance without effecting a change in its temperature is known as
- lost heat
- latent heat
- specific heat
- sensible heat
3: By using nitrogen within a pipe during brazing operation,
- Exterior scale formation is minimized
- Copper oxide formation is prevented
- The explosion hazard is confined
- Discoloration is prevented
4: Doors communicating with outside from a mechanical room must be?
- Self-closing, wooden, fire door
- Self-closing, aligned, fire door
- Steel, approved, weather-stripped
- Self-closing, approved, fire door
5: At higher altitudes, boiling temperatures
- depends on the refrigerant
- increase
- are unaffected
- decrease
6: A secondary coolant is defined as
- a combination of interconnected parts from a closed circuit in where fluid is circulated for the purpose of cooling for a refrigeration system.
- any refrigerant direcly in contact with the cooling space for process cooling
- a low temperature refrigerant used for cascading systems
- any liquid used for the transmission of heat without a change of state in A/C refrigeration systems having flash point above 150F
7: Clearance volume
- affects compressor capacity
- has no effect on compressor capacity
- varies depending on compressor speed
- is the same on all compressors
8: A 3-cubic foot receiver must have what type of relief valve?
- fusible plug
- relief valve
- rupture device
- none of the above
9: Sensible heat is the heat added to a substance to
- cause evaporation
- raise its temperature
- change its state
- freeze it
10: The actual expansion curve of compressor follows most nearly which one of the following
- Volume
- Isothermal
- Pressure-Temperature
- Adiabatic
11: What is the purpose of suction/discharge traps?
- to ensure proper oil return to the compressor
- to keep oil inside the evaporator for proper oil return to the compressor
- to keep oil inside of the accumulator for proper return to the compressor
- all of the above
12: The solution that leaves the concentrator in an absorption chiller is referred to as the
- diluted solution
- strong solution
- weak solution
- absorbed solution
13: Where must a refrigeration contractor's license number be displayed?
- Trucks, license plates, and uniforms
- Truck, office, every job, and on all equipment
- Trucks, invoices, and advertising
- Uniforms, checks, and invoices.
14: What device removes the start winding from the circuit of a split-phase motor once the motor reaches 75% of its rated load amps (RLA)?
- centrifugal switch
- printed circuit board (PCB)
- motor starter
- duel-voltage switch
15: If a halide torch is used for leak detection, what color is the flame if it detects a leak?
- red
- blue
- orange
- green
16: Institutional occupancy is
- a premise or that portion of a premise where large numbers of people congregate and from which occupants cannot quickly vacate the space.
- a premise or that portion of a premise from which, because they are disabled, debilitated, or confined, occupants cannot readily leave without the assistance of others.
- a premise or that portion of a premise where people transact business, receive personal service, or purchase food and other goods.
- None of the above
17: A capacitor in series with the start windings will do what?
- Increase starting torque
- Nothing
- Increase run efficiency by 10% of its rating
- Decrease the RLA to within 10% of its rating
18: What device should be used on low-temperature freezers?
- hot-gas by-pass
- oil separator
- discharge muffler
- high capacity TXV
19: What type of pressure relief device is used on a CO2 system?
- Gate valve
- Fusible plug
- Glove valve
- Rupture disk
20: If the power element of an expansion valve should lose its charge the valve would
- go open
- underfeed the evaporator
- go closed
- overfeed the evaporator
21: Which of the following is not an air velocity meter?
- Anemometer
- Hydrometer
- Anemotherm
- Velometer
22: What is not a requirement of a class T machine room?
- self-closing doors
- tight fitting doors
- automatic ventilation
- fire hose connection to the building fire protection system
23: What is the refrigerant chlorodifluoromethane?
- R-134a
- R-22
- R-123
- R-12
24: Which oil is hydoscopic?
- animal
- mineral
- SW30
- polyolester
25: Which refrigerant was still able to be vented to the atmosphere after July 1, 1992?
- R-12
- R-113
- R-22
- R-11