Topics: All categories in the pool
1: R-11 has the greatest corrosive effect on
- Magnesium
- Aluminum
- Copper
- Bronze
2: To determine the pump size needed for an open cooling tower system, the following must be known,
- GPM and unbalanced head and friction head
- GPM and balanced head and friction head
- GPM, pipe size, and equivalent head.
- GPM and friction head
3: The first step in mechanical refrigeration is
- condensation
- evaporation
- compression
- expansion
4: Three-phase motors have what type of windings?
- three run windings
- three run windings and 3 start windings
- three start windings
- one start winding and one run winding.
5: The boiling point of a refrigerant is based on
- Temperature
- Heat content
- a pressure-temperature relationship
- None of the above.
6: If the compression ratio on a centrifugal compressor rises too high, the compressor will stop pumping and make a loud sound commonly referred to as a
- splurge
- purge
- merge
- surge
7: The equivalent length of pipe in a water piping system is
- the total length of pipe plus equivalent of fittings multiplied by 2.31
- the total length of pipe as you would measure it plus 25% for fittigns
- the total length of pipe plus equivalent-length of fittings
- the total length of pipe as you would measure it
8: When liquid receivers are used, the liquid refrigerant shall not exceed _______percent of the volume at 90F.
- 90%
- 80%
- 99%
- 75%
9: The reversing valve is commonly used
- on all heat pumps
- on multiple compressor systems
- on commercial system that involve two different temperatures
- when the code requires a check valve
10: Ohm's Law indicates Amps X Resistance = ___________.
- Ohms
- Current
- Impedance
- Volts
11: 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
12: An example of an "Expendable Refrigerant" is
- ammonia
- liquid nitrogen
- lithium bromide
- liquid oxygen
13: Doors communicating with outside from a mechanical room must be?
- Steel, approved, weather-stripped
- Self-closing, approved, fire door
- Self-closing, wooden, fire door
- Self-closing, aligned, fire door
14: When an electronic bridge is in balance the bridge output will be
- 1 volt
- 15 volts
- 0 volts
- .01 volts
15: When a refrigeration or air conditioning system is installed
- the form of certificate shall be authorized by the Department of Pubic safety
- it shall not be operated below prescribed pressures
- it shall be approved by the owner for proper operation.
- a field inspection shall be made before it is put into service
16: Before you change the type of refrigerant in a refrigeration system, what three things must be done?
- Nothing must be done
- Make sure its compatible, notify owner, and notify AHJ.
- you can never change refrigerants
- Place sign, check for leaks, and insulate suction line
17: A multi-evaporator refrigeration system uses what type of valve to maintain evaporating temperatures?
- EPR valve
- Solenoid valve
- EEV
- CPR valve
18: 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
- 2,400 volts
- 24.0 volts
- 2.40 volts
- 240 volts
19: Pressure is equivalent of
- Force
- Force / Area
- Area X Force
- Force X Area
20: A motor starter is a device that includes an overload and a _______?
- contactor
- 2-pole contacts
- duel-coil
- all of the above
21: A movie theater would be considered a
- mixed occupancy
- institutional occupancy
- public assembly occupancy
- commercial occupancy
22: If a halide torch is used for leak detection, what color is the flame if it detects a leak?
- blue
- orange
- green
- red
23: At higher altitudes, boiling temperatures
- increase
- are unaffected
- depends on the refrigerant
- decrease
24: At higher altitudes, the boiling point of refrigerant is
- higher
- equal to the coefficient of water at 32F
- lower
- the same
25: 746 watts is equal to
- 1 hp
- Pi
- 100 hp
- 10 hp