Topics: All categories in the pool
1: What's the purpose of a megahmmeter?
- 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
2: A 120 volt motor rated at 1,800 watts. You find the motor is drawings 25 amps. The motor is
- drawing RLA and is running as it should
- drawing LRA and is seized and should be replaced.
- running hot
- none of the above
3: A person holding a license as a refrigeration technician may connect or disconnect for the purpose of installation, repair, or replacement, any electrical device or control to be a part of a refrigeration or air conditioning system, from the
- breaker panel in
- 24 volt secondary side of the Class 2 transformer to the thermostat
- load-side of the contactor in
- first disconnect in
4: When energized, a normally open relay will be
- closed
- noisy
- depends on the type and class of the relay
- open
5: A relief valve shall be located at least ___ above grade.
- 36'
- 25'
- 15'
- 10'
6: Pressure-limiting device isn't required on a factory-sealed system containing less than ____ lbs.
- 22
- 18
- 33
- 50
7: The level of voltage caused by back electromagnetic force that opens the contacts of a potential relay in order to take the start capacitor out of the circuit is
- boost voltage
- lift voltage
- pick-up voltage
- run voltage
8: An azeotropic refrigerant is
- a mixture of two or more refrigerants that boil at about the same temperature minimizing temperature glide.
- a mixture of two or more refrigerants that boil at much different temperatures causing temperature glide
- a mixture of two or more refrigerants that boil at much different temperatures minimizing temperature glide
- none of the above
9: Where a refrigeration or air conditioning system is installed,
- The company who installed the system must notify the fire department in the jurisdiction where installed
- A field inspection shall be made before it is put into service
- the form or certificate shall be authorized by the Department of Public Safety
- it shall not be operated below prescribed pressuers
10: 14.7 psia is equivalent to
- atmospheric pressure at seal level
- 29.92" Hg
- 0 psig
- All of the above.
11: There can be no airflow from an occupied space through a machine room unless what?
- System is high velocity
- System is ducted and sealed
- Duct is not located in the ceiling
- None of the above.
12: Pressure is the equivalent of
- area times force
- force times area
- force
- force per unit area
13: "R" represents ___ in the Ohm's law formula
- resistance
- voltage
- amperage
- capacitance
14: When can 50/50 solder be used?
- in the low side
- in the high side
- liquid and suction lines
- none of the above.
15: What is the refrigerant dichlorodifluoromethane?
- R-12
- R-123
- R-22
- R-134A
16: A capacitor in series with the start windings will do what?
- Increase run efficiency by 10% of its rating
- Nothing
- Increase starting torque
- Decrease the RLA to within 10% of its rating
17: What refrigerant were phased out in 2004?
- R-22
- R-134a
- R-12
- R-11
18: A split-phase motor has a ______ winding and a ____ winding
- run, common
- run, start
- start, common
- duel-run, duel-start
19: Name an HCFC refrigerant(s):
- R-22
- R-123
- R-11
- both a & b
20: A line voltage thermostat controls a 1,200 watt strip header at 120 volts. What must be minimum ampere rated of the stat be?
- 10 amps
- 15 amps
- 5 amps
- 20 amps
21: B3 refrigerants are considered
- non-toxic but non-flammable
- toxic but non-flammable
- toxic and highly flammable
- non-toxic but flammable
22: A declaration test is needed when the system contains more than
- 65 lbs
- 120 lbs
- 110 lbs
- 55 lbs
23: The actual expansion curve of compression follows most nearly which one of the following curves?
- Volume Temperature
- Isothermal
- Pressure Temperature
- Adiabatic
24: R-123 belongs to Group
- A-3
- B-1
- B-3
- B-2
25: If the power element of an expansion valve should lose its charge the valve would
- go closed
- underfeed the evaporator
- overfeed the evaporator
- go open