Topics: All categories in the pool
1: "E" represents _____ in the Watt's law formula.
- watts
- voltage
- amperage
- reactance
2: one BTU equals
- Pi
- 31.4 hp
- 12,000 hp
- 3.41 hp
3: Evaporators within 18" of a heating coil must be equipped with a
- pressure relief device
- low limit control
- zone valve
- high limit control
4: Heat that changes the physical state of a substance without effecting a change in its temperature is known as
- specific heat
- sensible heat
- lost heat
- latent heat
5: Brazed joints melt at temperatures above
- 1,000F
- 500F
- 800F
- 1,200F
6: A machine room with a refrigerant system using ammonia shall
- be provided with a continuously operated ventilation system
- be considered a non-hazardous location in accordance with National Electrical code
- have no flame producing apparatus permanently installed and operated
- All of the above
7: A normally operating R-410A system with a condensing temperature of 110F will have a high side pressure of around ______ psig
- 365 psig
- 327 psig
- 255 psig
- 125 psig
8: At higher altitudes, boiling temperatures
- increase
- are unaffected
- depends on the refrigerant
- decrease
9: The difference between saturated liquid and saturated vapor is
- temperature
- pressure
- heat
- volume
10: Pressure vessels with an internal volume of 3 cubic feet or less
- do not need pressure relief protection
- shall use pressure relief devices
- shall use fusible plugs
- shall use pressure relief devices or fusible plugs
11: A secondary coolant is defined as
- a low temperature refrigerant used for cascading systems
- any liquid used for the transmission of heat without a change of state in A/C refrigeration systems having flash point above 150F
- any refrigerant direcly in contact with the cooling space for process cooling
- a combination of interconnected parts from a closed circuit in where fluid is circulated for the purpose of cooling for a refrigeration system.
12: Group A2 refrigerants have a ______ toxicity rating than Group B1 refrigerants.
- the same
- lower
- higher
- there is no Group B1 refrigerants
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 can recovered refrigerants be reused?
- They can't
- Only when used in original owner's equipment
- Only if used in 30 days of recovery
- None of the above
15: 1 HP = ____ Watts?
- 3.1416
- 11,239
- 746
- 3,412
16: Which is considered the more efficient condenser?
- fan cooled
- air cooled
- water cooled
- spray cooled
17: On a single phase motor, when does the start winding cut out?
- 100% of its RLA speed
- 25% of its RLA speed
- 50% of its RLA speed
- 75% of its RLA speed
18: Halogen refrigerants are corrosive to which type of metal?
- copper
- black iron
- stainless steel
- magnesium
19: If a condenser is on a roof and the temperature is 35F and dropping the capacity
- increases
- decreases
- run as designed with low ambient controls
- doesn't change
20: System design pressures must take into consideration, not only, pressures found during normal operation but also what?
- When it's cold out
- When there is a malfunction on the high side
- When its warm out
- All of the above
21: A crankcase heater has a supplied voltage of 100 volts and is drawing 1.4 amps. What is the resistance?
- 104 ohms
- 71 ohms
- 27 ohms
- 80 ohms
22: The critical temperature of a refrigerant gas occurs when
- any increase in pressure will not liquefy the gas
- the gas returns to a liquid
- the gas is no longer saturated
- any decrease in pressure will cause condensation
23: An electrical circuit has a 208V power supply and draws 47 amps total, What would be the wattage of the circuit
- 977.6 watts
- 9,776 watts
- .9776 watts
- 9.776 watts
24: A 3-cubic foot receiver must have what type of relief valve?
- fusible plug
- relief valve
- rupture device
- none of the above
25: Low ambient controls are used when
- economizers are used
- on air conditioning systems only
- when systems run all year round
- always