Topics: All categories in the pool
1: What is a megaohm meter?
- Is an electric meter that measures extremely low resistance valves by sending high DC voltage signal into the object being tested.
- An electric meter used by electricians to test large 3-phase blower motors for the correct rotation
- An electric meter that measures very high resistance values by sending a low voltage AC signal into the object being tested
- An electric meter that measures very high resistance values by sending a high DC voltage signal into the object being tested
2: What's the purpose of a megohmmeter?
- To measure low to very low resistance values
- To alternate the current in a DC circuit in order to calculate the total impedance of a circuit
- To measure very high resistances
- None of the above
3: The actual expansion curve of compressor follows most nearly which one of the following
- Adiabatic
- Isothermal
- Volume
- Pressure-Temperature
4: Which refrigerant class listed below is the most flammable?
- C3
- B2
- A2
- A3
5: Pressure limiting devices are not required for systems containing less then ________ refrigerants.
- 22 lbs
- 6.6 lbs
- 13.9 lbs
- 44 lbs
6: A single pole-double throw switch used how many wires excluding the ground wire?
- two
- three
- five
- four
7: The maximum permissible amperage draw for a 40VA transfomer with a secondary voltage of 24V is
- .8
- 1.2
- .1
- 1.7
8: Low temperature systems should have what?
- High pour point
- Low pour point
- High viscosity
- None of the above
9: Thermodynamics is the branch of science that deals with
- state of energy
- heat energy
- energy due to motion
- molecular therory
10: Sublimation occurs when
- ice melts and turns to water
- gas is formed from a liquid
- gas is formed directly from a solid
- liquid is formed from a gas
11: How many forces operate a thermostatic expansion valve?
- 2
- 3
- 1
- 4
12: 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
13: How many groups of refrigerants are there?
- 7
- 5
- 1
- 3
14: A high side float is a
- metering device used on critically charged systems that controls the level of the liquid refrigerant in the high pressure side of the system.
- float type switch that stops the compressor when the pressure on the high side becomes too high
- float type valve that controls the amount of refrigerant stored in the receiver
- float type valve that controls the crankcase oil level
15: R-123 belongs to Group
- B-1
- B-2
- A-3
- B-3
16: Dual-pressure relief devices should be installed on
- vessels of 3 cubic feet or less
- vessels of 3 cubic feet or more
- vessels of 10 cubic feet or less
- vessels of 10 cubic feet or more
17: Starting relays for a single phase compressors are used to remove the starting circuit from operation when the motor reaches approximately ____ percent of its speed.
- 75
- 50
- 24
- 100
18: An example of an "Expendable Refrigerant" is
- liquid nitrogen
- lithium bromide
- ammonia
- liquid oxygen
19: Sensible heat is the heat added to a substance to
- raise its temperature
- freeze it
- cause evaporation
- change its state
20: The ASHRAE Standard 34 requires what type of alarm for equipment rooms using HCFC-123?
- CO Sensing
- A group sensing
- phosgene gas sening
- refrigerant sensing
21: What type of pressure relief device is used on a CO2 system?
- Rupture disk
- Fusible plug
- Glove valve
- Gate valve
22: 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)?
- duel-voltage switch
- printed circuit board (PCB)
- motor starter
- centrifugal switch
23: Which refrigerant(s) is an HFC?
- R-22
- R-410A
- R-502
- All of the above
24: What type of oil is used in R-410A systems?
- polyalkylene glycol (PAG)
- mineral oil
- naphthene
- polyolester (POE)
25: A High-Probablity system
- is such that a leak of refrigerant from failed connections will enter the unoccupied space
- 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 from a failed connection or component of such system
- is such that a leak of refrigerant from failed connections will enter the occupied space