Topics: All categories in the pool
1: one BTU equals
- 3.41 hp
- Pi
- 12,000 hp
- 31.4 hp
2: The best way to detect ammonia in brine is
- CO2 gas
- potassium of line
- nessler regaent
- carbonation of soda
3: The freezing point of water at sea level is?
- -10C
- 32F
- 32C
- 0F
4: Pressure relief devices are marked with a ____________ signifying compliance with the ASME Boiler & Pressure Vessel Code.
- UL and UR
- UL and UM
- UV or UR
- UM or UL
5: A premise where large numbers of people congregate and from which occupants can not quickly vacate the space is considered
- mixed occupancy
- commercial occupancy
- institutional occupancy
- public assembly occupancy
6: Ohm's Law indicates Amps X Resistance = ___________.
- Ohms
- Impedance
- Volts
- Current
7: How many closing forces operate a thermostatic expansion valve?
- 3
- 2
- 4
- 1
8: What is the minimum size of the discharge pipe?
- Same size as the outlet of the relief valve
- One pipe size larger that the inlet of the relief valve
- Depends on size of manifold
- All of the above
9: How does a centrifugal compressor create the pressure differential needed to move refrigerant through the system?
- Nesting scrolls
- Fan-like action
- Suction and discharge valves
- Rotating vanes
10: The critical temperature of a refrigerant gas occurs when
- the gas is no longer saturated
- the gas returns to a liquid
- any increase in pressure will not liquefy the gas
- any decrease in pressure will cause condensation
11: A self contained system
- is a complete factory made and tested system
- is a unit system Group I refrigerants only
- is a unit system Group II refrigerants only
- is any system or part of a system used to increase evaporation by expansion or vaporization
12: Which is the lowest vacuum?
- 1,000 Microns
- 5 psig
- 10 psia
- 5" hg
13: Refrigeration devices shall be equipped with a ____ to protect against unexpected pressure due to a malfunction or fire?
- T&P device
- Circuit Breaker
- Temperature limiter device
- Relief valve
14: Mercury was used in thermometers primarily because it
- never freezes
- expands uniformly
- vaporizes at very high temperatures
- was inexpensive
15: When should a relief valve start to function?
- Before the purge station discharges
- At it's set pressure
- 10 psi before it's set pressure
- Two times it's working pressure
16: A normally operating R-410A system with a condensing temperature of 110F will have a high side pressure of around ______ psig
- 255 psig
- 365 psig
- 327 psig
- 125 psig
17: Which of the following controllers would you expect to be most sensitive to temperature changes?
- low voltage t-stat
- line voltage t-stat
- immersion controller
- aquastat
18: A check valve is a device
- designed to allow the flow of refrigerant gas in both directions
- that is always spring loaded
- with a pressure drop
- found on high pressure steam systems
19: The critical temperature of a refrigerant gas occurs when
- any increase in pressure will not liquefy the gas
- any decrease in pressure will cause condensation
- the gas returns to a liquid
- the gas is no longer saturated
20: Pi equals approximately
- 746
- 3.41
- 12,000
- 3.14
21: How many flammability classifications are refrigerants in?
- 3
- 7
- 2
- 5
22: A 24 volt transformer with a 240 volt primary can handle how many amps?
- 20 amps
- 24 amps
- 10 amps
- There isn't enough information to answer.
23: A motor starter contains a thermal overload and a
- contactor
- transformer
- 3-way relay
- solenoid
24: Sensible heat is the heat added to a substance to
- freeze it
- change its state
- raise its temperature
- cause evaporation
25: Which occupancy can ammonia be used in?
- depends on the quantity of freon
- industrial
- redifential
- commercial