Topics: All categories in the pool
1: Which occupancy can ammonia be used in?
- industrial
- depends on the quantity of freon
- commercial
- redifential
2: Instead of using a compressor, an absorption air-conditioning chiller uses which of the following as its driving force?
- Electricity
- Oil
- Heat
- Air
3: Increasing superheat will do what to your frost line?
- Could either increase or decrease depending on the load conditions
- Decrease
- Nothing
- Increasae
4: Viscosity is
- the coefficient of external friction
- a measure of heat content
- the ability of oil to flow
- measure of weight
5: What device measures the specific gravity of a substance?
- Hygrometer
- Manometer
- Thermometer
- Hydrometer
6: To determine the pump size needed for an open cooling tower system, the following must be known,
- GPM and friction head
- GPM and balanced head and friction head
- GPM, pipe size, and equivalent head.
- GPM and unbalanced head and friction head
7: How many forces operate a thermostatic expansion valve?
- 4
- 3
- 1
- 2
8: What refrigerant doesn't have to be classified?
- R-718
- R-134A
- R-422A
- R-717
9: Clearance volume
- affects compressor capacity
- has no effect on compressor capacity
- varies depending on compressor speed
- is the same on all compressors
10: What must be done to refrigerant pipes before being buried ?(8.10.4)
- Leak checked
- Classifed
- Insulated and installed in a pipe duct (Encased)
- Certified
11: Pipe identification labels are required when the system contains more than
- 110 lbs
- 120 lbs
- 65 lbs
- 55 lbs
12: A crankcase heater has a supplied voltage of 100 volts and is drawing 1.4 amps. What is the resistance?
- 71 ohms
- 80 ohms
- 27 ohms
- 104 ohms
13: Where is an EPR valve located on a multi-evaporator system?
- Suction line of the warmest evaporator
- Suction line of the coolest evaporator
- Suction line at the compressor
- Suction line prior to the accumulator of the lowest temperature system
14: If a halide torch is used for leak detection, what color is the flame if it detects a leak?
- red
- green
- blue
- orange
15: What percentage of amperage difference is allowable phase to phase on a HVAC circuit phased to phase?
- 1%
- 4%
- 2%
- 25%
16: How many refrigerant classifications are there for toxicity?
- 5
- 2
- 1
- 3
17: A mercury bulb controller is not recommended for
- line or low voltage use
- low voltage use
- use where vibration is severe
- line voltage use
18: Liquid level gauges must be provided with what?
- A relief valve
- A red line
- A low level mark
- Automatic shut-offs
19: What is R-22?
- Chlorodifluoromethane
- Chlorofluoromethane
- HFC
- CCFCM
20: Which of the following is an example of an azeotropic refrigerant?
- R-134A
- R-404A
- R-410A
- R-500
21: What device should be used on low-temperature freezers?
- discharge muffler
- high capacity TXV
- oil separator
- hot-gas by-pass
22: What is not a requirement of a class T machine room?
- fire hose connection to the building fire protection system
- self-closing doors
- tight fitting doors
- automatic ventilation
23: Capacity control on a centrifugal compressor is accomplished by the
- post-rotational guide vanes
- slide vanes
- pre-rotational guide vanes
- check valves
24: What is the boiling point of refrigerant governed by?
- P&T relationship
- Evaporator temperature
- Condenser sub-cooling
- Compressor RPM's
25: Heat is a form of
- matter
- work
- power
- energy