Topics: All categories in the pool
1: Lithium-bromide, Li-Br, is best characterized as a
- sugar
- salt
- soil
- sand
2: What is the refrigerant dichlorodifluoromethane?
- R-123
- R-22
- R-12
- R-134A
3: How do you find net oil pressure on a compressor?
- discharge pressure - suction pressure
- gross oil pressure - suction pressure
- gross oil pressure - discharge pressure
- all of the above
4: Calculate the voltage in a series circuit when the total amperage is 10 amps and the resistors have values of: R1=12 ohms, R2=8 ohms, R3=4 ohms
- 240 volts
- 24.0 volts
- 2,400 volts
- 2.40 volts
5: Can a R22 line set be reused for a 410A system and if it can be reused, what must be done to it?
- Flush with R-718
- Flush with R-11
- Flush with RX-11
- Flush with ammonia
6: Refrigerant restricted in 2004 but used for transition for decades:
- R-123
- R-11
- R-22
- R-134A
7: How many volts would you read on a 480V system phase to phase?
- 1/3 the voltage
- 0
- 277
- 480
8: Class A refrigerants are considered
- non-flammable
- flammable
- toxic
- non-toxic
9: Refrigerant is metered into the evaporator on a large centrifugal chiller thru the
- low side of the system
- high side float assembly
- cap tube
- none of the above
10: What device measures the specific gravity of a substance?
- Thermometer
- Manometer
- Hygrometer
- Hydrometer
11: A split-phase motor has a ______ winding and a ____ winding
- start, common
- run, common
- run, start
- duel-run, duel-start
12: Group A1 refrigerants over ____ pounds in a system must discharge to the atmosphere
- 1,000
- 6.6
- 330
- 110
13: A single pole-double throw switch used how many wires excluding the ground wire?
- two
- four
- three
- five
14: Halogen refrigerants are corrosive to which type of metal?
- copper
- stainless steel
- black iron
- magnesium
15: Pressure vessels with an internal volume of 10 cubic feet or more
- shall use pressure relief devices
- shall use fusible plugs
- shall use rupture discs or duel pressure relief valves
- shall use pressure relief devices or fusible plugs
16: What is the voltage of each leg to ground of a three-phase motor with a 460v supply voltage?
- 120v
- 277v
- 240v
- 208v
17: Pressure is the equivalent of
- force
- area times force
- force times area
- force per unit area
18: The test pressure applied to the high side of each factory-assembled refrigerating system shall be at least equal to the design pressure of
- the high side
- the aggregate of the high side and low side
- 2.5 times the design pressure
- the low side
19: The amount of heat required to raise the temperature of 1 lb of water 1F is?
- 1 BTU
- The rate of conduction
- 1 Kelvin
- 1 Therm
20: All electrical work done on refrigeration systems must comply with
- NEC and Massachusetts Modifications
- OSHA
- Department of Energy
- ASHREA-15 Section 9.2.1
21: The heat picked up in the evaporator must equal to
- the heat gained by the condenser
- the heat of compression
- the heat lost by the medium being cooled
- the heat giving by the condenser
22: Which of the following most closely represents the concentration of Li-Br in a absorption system?
- 60% Li-Br, 40% distilled water
- 50% Li-Br, 50% tap water
- 40% Li-Br, 60% distilled water
- 40% Li-Br, 60% tap water
23: On cooling towers, what causes the condenser water to drop
- ambient temperatures
- tower fans
- sensible heat
- evaporation of the water droplets
24: Setting a pressure relief device shall not exceed ___ of the design pressure
- 100%
- 75%
- 90%
- 80%
25: A High-Probability System
- is such that any leak will cause injury or death to anyone within a 100 square foot area
- is a system highly likely to leak form a failed connection or component of such system
- is such that a leak of refrigerant from a failed connection will enter an unoccupied space
- is such that a leak of refrigerant from a failed connection will enter the occupied space