391)
391)
Define critical point.
A)
The pressure and temperature where a substance can exist simultaneously as a solid, a
liquid, and a gas in thermal equilibrium
B)
The pressure and temperature where a solid and a liquid have the same properties
C)
The pressure and temperature at which gas and liquid have the same properties
D)
The pressure and temperature above which a substance will cease to exist
Answer:
C
Explanation:
392)
392)
A vapor that changes into a solid while bypassing the liquid state is known as:
A)
Critical mass.
B)
Critical pressure.
C)
Deposition.
D)
Critical temperature.
Answer:
C
Explanation:
393)
393)
If something has a high density:
A)
Its specific volume is also likely to be high.
B)
There is no relationship between density and specific volume.
C)
Its specific volume is likely to be low.
D)
Its specific gravity is likely to be low.
Answer:
C
Explanation:
394)
394)
Which is occurring when gaseous molecules release heat and join together to form a liquid?
A)
Melting
B)
Evaporating
C)
Condensing
D)
Solidifying
Answer:
C
Explanation:
101
395)
395)
The law of conservation of matter states that:
A)
An equal amount of matter is always created somewhere whenever matter is destroyed.
B)
Matter cannot be created or destroyed.
C)
Matter should not be wasted.
D)
Only “green” matter should be used for installing HVACR systems.
Answer:
B
Explanation:
396)
396)
Because liquids are noncompressible:
A)
Their volumes change only when atmospheric pressure changes.
B)
Their volumes will not change when pressures change.
C)
They are not susceptible to changes in volumetric efficiency.
D)
The volume changes in relationship to pressure change when contained.
Answer:
B
Explanation:
397)
397)
The melting point of solid materials:
A)
Is the change of state of a substance from a solid to a liquid at a given pressure and
temperature when heat is added.
B)
Is 100°C.
C)
Is 212°F.
D)
Never considers pressures or temperatures.
Answer:
A
Explanation:
398)
398)
Size, form, shape, and state relate to:
A)
The structure of matter.
B)
The physical state of matter.
C)
The critical point of matter.
D)
The chemical state of matter.
Answer:
B
Explanation:
102
399)
399)
If a material or substance in the state of a liquid or solid has a specific gravity less than ________ it
will float.
A)
0.5
B)
1.5
C)
1.0
D)
2.0
Answer:
C
Explanation:
400)
400)
Hot air is:
A)
More dense than warm air.
B)
More dense than cold air.
C)
Equal in density with warm or cold air at the same barometric pressure.
D)
Less dense than warm air.
Answer:
D
Explanation:
401)
401)
Which units can be used to describe the density of a substance?
A)
Feet per square pound
B)
Pounds per cubic foot
C)
Pounds per square foot
D)
Cubic feet per pound
Answer:
B
Explanation:
402)
402)
What physical change of state is the opposite of evaporation?
A)
Freezing
B)
Melting
C)
Condensation
D)
Sublimation
Answer:
C
Explanation:
103
403)
403)
Atoms are composed of:
A)
Protons, neutrinos, and electrons.
B)
Positrons, neutrinos, and electrons.
C)
Positrons, neutrons, and electrons.
D)
Protons, neutrons, and electrons.
Answer:
D
Explanation:
404)
404)
Mass measures:
A)
How much matter an object has.
B)
Only the specific gravity of a liquid.
C)
Only the specific volume of a substance.
D)
Only the density of a solid.
Answer:
A
Explanation:
405)
405)
Standard atmospheric pressure is:
A)
29.92 in Hg.
B)
14.7 psig.
C)
30 psia.
D)
0 psia.
Answer:
A
Explanation:
406)
406)
The state of matter depends upon:
A)
Its temperature and pressure.
B)
Only on its pressure.
C)
Only on its temperature.
D)
The state of matter is not affected by either pressure or temperature.
Answer:
A
Explanation:
104
407)
407)
The substance used to compare the specific gravity of gases is:
A)
Air.
B)
Oxygen.
C)
Nitrogen.
D)
Helium.
Answer:
A
Explanation:
408)
408)
Solids contain ________ amount of energy within materials or substances when they are in their
various physical states.
A)
the least
B)
the equivalent
C)
the highest
D)
a variable
Answer:
A
Explanation:
409)
409)
Which form of matter has neither a definite shape nor definite volume?
A)
Solid
B)
Liquid
C)
Gas
Answer:
C
Explanation:
410)
410)
Changes in the volume of a gas can happen:
A)
Only if the size of the container changes.
B)
Whenever there is a change in temperature.
C)
Anytime the ambient temperature changes and the volume of the container doesn’t change.
D)
Only if there is a change in barometric pressure.
Answer:
B
Explanation:
105
411)
411)
Liquid achieves its boiling point:
A)
When the vapor point of the gas bubbles in a liquid becomes equal to the pressure
surrounding the liquid.
B)
It is below its critical pressure.
C)
When the vapor point of the gas bubbles in a liquid becomes lower than the pressure
surrounding the liquid.
D)
When the liquid has reached its critical mass.
Answer:
A
Explanation:
412)
412)
Matter can best be described as:
A)
Only substances that can change their state from liquid to vapor.
B)
Anything that has mass and occupies space.
C)
Only substances that can change state from liquid to solid.
D)
Substances that undergo adiabatic changes when heated or cooled.
Answer:
B
Explanation:
413)
413)
When a substance in the liquid state occupies a container, it:
A)
Applies twice the pressure to the bottom of the container directly proportional to the sides
and surface.
B)
Applies the greatest amount of pressure on the bottom of the container.
C)
Applies pressure equally to the bottom and the sides of the container.
D)
Applies pressure to only the bottom of the container due to force of barometric pressure.
Answer:
B
Explanation:
106
414)
414)
A characteristic of water vapor, but not other states of water, is:
A)
Water vapor is compressible.
B)
Water exerts equal pressure on the sides of a container in which it is placed.
C)
Small changes in the volume of water occur with changes in temperature.
D)
Water molecules move about freely.
Answer:
A
Explanation:
415)
415)
The ________ set of standard conditions are used to reference pressure and temperature when
calculating specific gravity and specific volume of substances.
A)
RSES
B)
ACCA
C)
AHRI
D)
ASHRAE
Answer:
C
Explanation:
416)
416)
When sizing a compressor for a refrigeration application, the compressor is rated by: (TECH TIP)
A)
The size of the refrigerated space.
B)
The amount of refrigerant in cubic feet the compressor can move.
C)
The amount of time in which the compressor can move a pound of refrigerant through the
evaporator.
D)
The number of pounds of refrigerant the compressor pumps per hour.
Answer:
B
Explanation:
417)
417)
Where is heated air most likely to settle in a room?
A)
Near the floor
B)
Midway between the ceiling and the floor
C)
Near the ceiling
D)
Dispersed evenly throughout the room
Answer:
C
Explanation:
107
418)
418)
Which form of matter has both a definite shape and volume?
A)
Solid
B)
Liquid
C)
Gas
Answer:
A
Explanation:
419)
419)
If a gas with a specific gravity of 1.3 is released in a room, will it be more likely to be found near
the ceiling or near the floor?
A)
Near the floor because its specific gravity is greater than 1.
B)
It would be found at both the ceiling and the floor because a gas with a high specific gravity
would fill up the room.
C)
Near the ceiling because its specific gravity is greater than 1.
D)
The specific gravity of a gas does not affect its position in a room relative to other gases.
Answer:
A
Explanation:
420)
420)
Raising the pressure inside a closed container ________ the boiling point of a liquid.
A)
decreases
B)
increases
C)
has no effect on
D)
eliminates
Answer:
B
Explanation:
421)
421)
The specific volume of a gas that occupies 30 cubic feet and weighs 3 pounds is:
A)
Specific volume = 30 ft3+ 3 lb = 33 lb/ft 3.
B)
Specific volume = 3 lb × 30 ft3= 900 lb/ft 3.
C)
Specific volume = 30 ft3/3 lb = 10 ft3/lb.
D)
Specific volume = 3 lb/30 ft3= 0.1 lb/ft 3.
Answer:
C
Explanation:
108
MATCHING. Choose the item in column 2 that best matches each item in column 1.
Match the trade organization with its constituency.
422)
Refrigeration service technicians
Answer:
A
A)
RSES
422)
Match the level of current passing through the body with the physiological effect.
423)
Pain
Answer:
A
A)
30 milliamps and up
423)
Match the trade organization with its constituency.
424)
HVACR contractors
Answer:
A
A)
ACCA
424)
Match the level of current passing through the body with the physiological effect.
425)
Probable death
Answer:
A
A)
100 milliamps and above
425)
Match the trade organization with its constituency.
426)
HVACR engineers
Answer:
A
A)
ASHRAE
426)
Match the fire extinguisher class with the type of fire.
427)
Electrical fires
Answer:
A
A)
Class C
427)
Match the trade organization with its constituency.
428)
HVACR manufacturers
Answer:
A
A)
AHRI
428)
Match the level of current passing through the body with the physiological effect.
429)
Severe pain and muscle contractions
Answer:
A
A)
50 milliamps and above
429)
Match the fire extinguisher class with the type of fire.
430)
Ordinary combustibles
Answer:
A
A)
Class A
430)
109
Match the level of current passing through the body with the physiological effect.
431)
You can start to feel the current.
Answer:
A
A)
1–30 milliamps
431)
Match the fire extinguisher class with the type of fire.
432)
Flammable liquids
Answer:
A
433)
Combustible metals
Answer:
B
A)
Class B
B)
Class D
432)
433)
110
Answer Key
Testname: UNIT 1 TO 10
1)
A
2)
A
3)
C
4)
D
5)
A
6)
D
7)
C
8)
B
9)
A
10)
A
11)
C
12)
A
13)
D
14)
A
15)
C
16)
D
17)
A
18)
D
19)
B
20)
D
21)
C
22)
D
23)
D
24)
A
25)
B
26)
D
27)
C
28)
D
29)
D
30)
C
31)
D
32)
A
33)
C
34)
A
35)
B
36)
D
37)
A
38)
C
39)
B
40)
A
41)
C
42)
A
111