WorksheetsHVAC Random 25-01
Total questions: 25
Worksheet time: 13mins
Name
Class
Date
1.
Heat of fusion of water, is the heat released from a substance to change irt from a liquid state to a solid state. The heat of fusion of ice is ___ Btu per pound.
a)
144
b)
109
c)
42
d)
31
2.
Select one of the most common result produced by a small difference in a system.
a)
short cycling
b)
temperatures that are too low
c)
long off periods
d)
an iced coil
3.
Avoid contact with contaminated lubricant from a hermetic system that is dirty and smells bad because it may be
a)
acidic
b)
explosive
c)
phosgenic
d)
radioactive
4.
In many condensing unit applications, it is necessary to heat the compressor to evaporate liquid refrigerant trapped in the oil. Most large compressors for commercial applications are manufactured and equipped to handle this situation using a ___.
a)
crankcase heater
b)
low temperature heating circuit
c)
high temperature cooling circuit
d)
off cycle oil pressure reducer
5.
What does a sling psychrometer measure directly?
a)
temperature and dew point
b)
heat and cold
c)
gain and drops
d)
wet bulb and dry bulb
6.
Materials within plenums shall be noncombustible or shall have a smoke-developed index of NOT MORE THAN ____ when tested in accordance with ASTME E 84.
a)
450
b)
250
c)
50
d)
25
7.
Which component may be added to a refrigeration system to prvent moisture from entering the compressor?
a)
receiver
b)
accumulator
c)
liquid line filter drier
d)
crankcase pressure regulator
8.
If a vessel of AT LEAST ____ deep with an open top is labeled a confined space.
a)
8 feet
b)
6 feet
c)
4 feet
d)
2 feet
9.
What is the applied voltage across an electric heater with a total current draw of 22 amperes and a resistance of 11 ohms?
a)
230
b)
240
c)
242
d)
248
10.
Mechanical joints, in a refrigeration system, shall not be used on annealed temper copper tube in sizes larger than ___ OD size.
a)
7/8 inch OD
b)
1 1/8 inches OD
c)
5/8 inch OD
d)
3/4 inch OD
11.
Which of the following options is FALSE about uncoated metallic ducts installed under concrete slabs:
a)
sloped to an accessible plenum for drainage
b)
accessible for cleaning
c)
encased on all sides with a minimum of 2 inches of concrete
d)
properly sealed and secured prior to encasement
12.
Tags were placed to identify equipment on which some work is being done. Also, this equipment must not be operated until further notice. According to OSHA, the tags shall be attached to:
a)
all points where the equipment can be energized
b)
the place where the equipment is being worked on
c)
the point where the main source of energy is connected
d)
all places where the equipment touches the ground
13.
It is required that combustion air enetering and leaving a furnace to be keeped as clean as possible. Combustion air opening that do not terminate in the attic space should have a ____ installed.
a)
a fine mesh screen
b)
back draft damper
c)
fire damper
d)
volume damper
14.
A device that separates the low pressure liquid side of a refrigeration system from the high pressure liquid side is called the
a)
receiver
b)
expansion valve
c)
compressor
d)
condenser
15.
A permanent factory-applied nameplare (s) shall be affixed to appliances on which shall appear in legible lettering. From the list below, choose the one item that DOES NOt need to be included on the nameplate.
a)
required clearances from combustible construction
b)
type of fuel approved
c)
control schematic
d)
fuel rating in Btu/h
16.
How is a fan motor connected electrically to the compressor or motor control?
a)
in parallel and controlled by refrigerant control
b)
in parallel and controlled by thermostat
c)
in series and controlled by refrigerant control
d)
in series and controlled by thermostat
17.
Combustion is a chemical process of rapid oxidation in which fuel and oxygen produce
a)
energy.
b)
water vapor.
c)
carbon dioxide.
d)
heat and light
18.
It is required that combustion air entering and leaving a furnace to be keep as clean as possible. COmbustion air opening that do not terminate in the attic space should have a ___ installed.
a)
a fine mesh screen
b)
back draft damper
c)
fire damper
d)
volume damper
19.
What is the heat of fusion of water?
a)
-109 Btu/lb
b)
41 Btu/lb
c)
32 Btu/lb
d)
144 Btu/lb
20.
Where gypsum products are exposed in ducts or plenums, the air temperature shall NOT exceed ___ degrees F.
a)
100
b)
125
c)
150
d)
175
21.
Certain refrigerants cause a flame to turn green when passing over a hot copper strip. What tool uses this effect to detect leaks?
a)
A welding torch
b)
An infra red torch
c)
An ultraviolet torch
d)
A halide torch
22.
According to the International Fire Code, duct smoke detectors in heating and AC systems must be connected to what?
a)
fire department
b)
electrical supply to the building
c)
gas supply to the building
d)
the building fire alarm system
23.
What type of circuit has only a single path for current to flow?
a)
parallel circuit
b)
series circuit
c)
low voltage circuit
d)
high voltage circuit
24.
Equipment and appliances having an ignition source shall be elevated such that the source of ignition is not less than ___ above the floor in hazardous locations and public garages, and motor fuel-dispensing facilities.
a)
6"
b)
12"
c)
18"
d)
20" or more
25.
What is a by-product of incomplete combustion due to an insufficient amount of combustion air/
a)
phosgene gas
b)
benzyl bromide
c)
carbon dioxide
d)
carbon monoxide
100 %
