Topics: All categories in the pool
1: The normal operating evaporator temperature of R-410A for air conditioning is typically
- 155F
- 158F
- 45F
- 32F
2: What is the minimum size wire you can use on a 30 amp circuit?
- 10 AWG
- 12 AWG
- 16 AWG
- 14 AWG
3: A thermometer inside a duct measures ____ heat.
- specific
- hidden
- latent
- sensible
4: When testing systems using non-positive displacement compressors, the entire system shall be considered for test purposes as the low side.
- True
- False
5: An air conditioning system rated for 36,000 BTU's is equivalent to
- one ton of cooling
- 12,000 tons of cooling
- two tons of cooling
- three tons of cooling
6: Gauge pressure is
- atmospheric pressure
- what a gauge reads when checking pressures on a chilled water system.
- force of pressure above that of atmospheric
- absolute pressure
7: Usually dry bulb temperature is
- higher than wet bulb temperature
- not important and shall be ignored
- lower than dry bulb temperature
- same as wet bulb temperature
8: Which of the following is an inorganic refrigerant?
- R-22
- Ammonia
- Chlorofluorocarbons
- All of the above
9: In a horizontal shell & tube condenser, the ammonia is liquefied by
- water sprayed over condenser
- removing the latent heat of vaporization
- passing thru the tubes from top to bottom
- removing the latent heat of fusion
10: When an inspection is needed, how often must it be done?
- every 24 months
- every 36 months
- every 18 months
- annually
11: A halide torch is most useful with a freon compression system
- to detect refrigeration leaks in piping joints
- to sweat flanges on the refrigeration piping
- to release a sticking valve
- to remove from from TXV's and evaporator coils
12: What are the three components of a transformer?
- Contacts, secondary coil, and core
- Primary coil, secondary coil, and copper contacts
- Primary coil, secondary coil, and core
- Primary core, secondary coil, and high and low voltage connectors.
13: What does an anemometer measure?
- voltage
- amperage
- velocity
- temperature
14: Which of the following is NOT a positive displacement compressor?
- screw
- scroll
- centrifugal
- reciprocating
15: It takes how many BTU/hr to melt one pound of ice at 32F
- 144
- 212
- 180
- 970
16: The heat picked up in the evaporator must equal to
- the heat giving by the condenser
- the heat gained by the condenser
- the heat of compression
- the heat lost by the medium being cooled
17: What is the purpose of a surge capacitor on a contactor?
- to protect low voltage equipment
- to provide smoother start/stops
- to balance the sine waves
- to keep the contactor pulled in
18: The amount of heat required to raise the temperature of 1 lb of water 1F is?
- 1 Kelvin
- The rate of conduction
- 1 BTU
- 1 Therm
19: Pressure relief devices are marked with a ____________ signifying compliance with the ASME Boiler & Pressure Vessel Code.
- UL and UM
- UL and UR
- UV or UR
- UM or UL
20: What happens to copper joints when overheated?
- nothing
- joint becomes oxidized and ditorted
- copper becomes harder
- none of the above
21: What type of copper is not permitted on refrigeration systems?
- Type N
- Type L
- Type M
- Type K
22: Laten heat is associated with a change in state of a refrigerant but not temperature
- True
- False
23: A low oil switch is typically
- manual reset
- time-delay auto reset
- automatic reset
- non used on semi-hermetic compressors over 10 ton capacity
24: If the power element on an expansion valve should lose its charge, the valve would
- Under feed
- Stay open
- Over feed
- Close
25: Electricity involves the movement of electrons in atoms
- True
- False