Topics: All categories in the pool
1: Refrigeration devices shall be equipped with a ____ to protect against unexpected pressure due to a malfunction or fire?
- Temperature limiter device
- T&P device
- Circuit Breaker
- Relief valve
2: Mercury was used in thermometers primarily because it
- was inexpensive
- never freezes
- vaporizes at very high temperatures
- expands uniformly
3: Increasing superheat will do what to your frost line?
- Could either increase or decrease depending on the load conditions
- Decrease
- Nothing
- Increasae
4: In an ammonia refrigerating system, how is oil pressure adjusted?
- Outlet of pump
- Inlet of pump
- Spring tension of a pressure regulating valve
- Both a & b are correct
5: Can you use Ammonia in industrial applications?
- No, never
- When mixed with R-718
- Yes, always
- Yes, Under certain condidtions
6: Pressure vessels of 10 cubic feet or more gross volume shall use
- at least one rupture member
- a dual pressure-relief valve if charging into the atmosphere
- at least three means of discharge and/or rupture discs
- both a and b are correct
7: "R" represents ___ in the Ohm's law formula
- voltage
- capacitance
- resistance
- amperage
8: Viscosity is
- a measure of heat content
- the coefficient of external friction
- measure of weight
- the ability of oil to flow
9: Insurance companies shall forward each inspection report of all refrigeration or A/C systems to the Chief of Inspections within
- 30 days
- 2 months
- 14 days
- 1 week
10: How many CFMs are required per square foot of commercial office occupied space
- .5 CFM
- 5 CFM
- 15 CFM
- 20 CFM
11: What is a Category "D" fluid?
- A fluid which is nonflammable, nontoxic, not damaging to human tissues, does not exceed 150 psig, and design temperature is between -20F to 366F
- A toxic fluid, which can produce serious irreversible harm to persons on breathing or bodily contact
- Any fluid that exceeds 150 psig and has design temperature of over 366F
- A typical refrigerant used on newer air conditioning and heat pump ssytems
12: What instrument is used to measure very high resistance?
- ammeter
- meg ohmmeter
- voltmeter
- tape measure
13: _____ and its alloys are suitable for use with ammonia systems.
- Copper
- Aluminum
- Magnesium
- Zinc
14: How many groups of refrigerants are there?
- 1
- 3
- 7
- 5
15: A capacitor in series with the start windings will do what?
- Nothing
- Increase run efficiency by 10% of its rating
- Increase starting torque
- Decrease the RLA to within 10% of its rating
16: Class 3 refrigerants are
- non-toxic
- toxic
- highly flammable
- non-flammable
17: If the suction pressure is low and the evaporator temperature high, the cause will be a?
- starved evaporator
- too small evaporator
- overcharged
- compressor suction valve stuck open
18: Ammonia belongs to Group
- B-1
- A-1
- B-2
- A-2
19: A High-Probability System
- is a system highly likely to leak form a failed connection or component of such system
- is such that a leak of refrigerant from a failed connection will enter the occupied space
- is such that a leak of refrigerant from a failed connection will enter an unoccupied space
- is such that any leak will cause injury or death to anyone within a 100 square foot area
20: Sensible heat is the heat added to a substance to
- change its state
- cause evaporation
- raise its temperature
- freeze it
21: At higher altitudes, the boiling point of refrigerant is
- the same
- lower
- higher
- equal to the coefficient of water at 32F
22: The generator shell contains the
- condenser and the absorber
- condenser, the evaporator, and the generator
- evaporator and the absorber
- condenser and the generator
23: A halide torch is most useful with a freon compression system
- to sweat flanges on the refrigeration piping
- to remove from from TXV's and evaporator coils
- to detect refrigeration leaks in piping joints
- to release a sticking valve
24: The test pressure applied to the high side of each factory-assembled refrigerating system shall be at least equal to the design pressure of
- the low side
- 2.5 times the design pressure
- the high side
- the aggregate of the high side and low side
25: Brazed joints melt at temperatures above
- 1,200F
- 800F
- 500F
- 1,000F