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157)
157)
Units in the SI measurement system are subdivided into:
A)
Units of 10.
B)
Units divisible by 2.
C)
Common fractional quantities.
D)
Units divisible by 3.
Answer:
A
Explanation:
A)
B)
C)
D)
158)
158)
A container is half full of liquid. If the temperature of the liquid is increased, the liquid volume:
A)
Will decrease and the empty space remaining in the container will increase.
B)
Will remain the same because liquid volume is not affected by temperature.
C)
Will increase and the empty space remaining in the container also will increase.
D)
Will increase and the empty space remaining in the container will decrease.
Answer:
D
Explanation:
A)
B)
C)
D)
159)
159)
How do environmental variables complicate HVACR testing?
A)
When completed, the tester must note testing conditions and type of HVACR testing.
B)
Testing conditions, such as air pressure and temperature, can affect testing.
C)
Environmental conditions have little impact on testing.
D)
Many types of HVACR testing, organizations, and standards exist.
Answer:
B
Explanation:
A)
B)
C)
D)
160)
160)
There are two areas into which the properties of matter can be divided:
A)
Specific gravity and specific volume.
B)
Physical and chemical.
C)
Pressures above and below atmospheric pressure.
D)
Temperatures above and below 70°F.
Answer:
B
Explanation:
A)
B)
C)
D)
41
161)
161)
Weight is defined as:
A)
The amount of time it takes an object to achieve terminal velocity.
B)
The force of gravity acting upon an object.
C)
Mass = force × distance.
D)
Mass = force ÷ distance.
Answer:
B
Explanation:
A)
B)
C)
D)
162)
162)
Water will evaporate at a slower rate when:
A)
The temperature of the water is below the point of vaporization.
B)
The ambient air around it is at a low relative humidity.
C)
The relative humidity is high
D)
The dew point is equal to barometric pressure.
Answer:
C
Explanation:
A)
B)
C)
D)
163)
163)
The specific gravity of water is:
A)
1.0.
B)
0.1.
C)
5.0.
D)
10.0.
Answer:
A
Explanation:
A)
B)
C)
D)
164)
164)
The most relevant standard that applies to air-conditioning technicians is:
A)
AHRI standard "A."
B)
ANSI standard "B."
C)
ACCA standard "C."
D)
ASHRAE standard "A."
Answer:
A
Explanation:
A)
B)
C)
D)
42
165)
165)
Which form of matter has a definite volume, but takes the shape of its container?
A)
Solid
B)
Liquid
C)
Gas
Answer:
B
Explanation:
A)
B)
C)
166)
166)
As an air-conditioning and refrigeration technician, which of the following states of matter will
you use in your job?
A)
Solid, liquid, and gas
B)
Gas and liquid
C)
Liquid and solid
D)
Solid only
Answer:
A
Explanation:
A)
B)
C)
D)
167)
167)
The three common states of matter are:
A)
Sensible, latent, and specific.
B)
Subatomic, atomic, and molecular.
C)
Radiant, conductive, and convective.
D)
Solid, liquid, and gas.
Answer:
D
Explanation:
A)
B)
C)
D)
168)
168)
The definition of sublimation is:
A)
A substance in a solid state changes into the gaseous state without going through the liquid
state.
B)
In a closed container, a substance in the liquid state boils at a higher temperature when the
pressure is increased.
C)
A substance in a gaseous state changes into a solid state while bypassing the liquid state.
D)
In a closed container, a substance in a liquid state remains in a liquid state regardless of the
pressure inside the container.
Answer:
A
Explanation:
A)
B)
C)
D)
43
169)
169)
According to the law of conservation, when matter changes state its ________ remains the same.
A)
volume
B)
temperature
C)
mass
D)
energy
Answer:
C
Explanation:
A)
B)
C)
D)
170)
170)
The temperature of the water formed by melting ice is:
A)
33°F.
B)
32°F.
C)
31°F.
D)
Ambient temperature.
Answer:
B
Explanation:
A)
B)
C)
D)
171)
171)
The molecules of gases have:
A)
The same levels of energy as solids and liquids when contained.
B)
Lower levels of energy than solids or liquids due to molecular instability.
C)
Higher energy levels than solids or liquids.
D)
Higher levels of energy than solids or liquids only when exposed to temperature changes.
Answer:
C
Explanation:
A)
B)
C)
D)
172)
172)
Natural gas floats on air. What does this tell us about its properties?
A)
It has a higher specific gravity than air.
B)
It has a higher density than air.
C)
It has a lower specific gravity than air.
D)
It has a lower volume than air.
Answer:
C
Explanation:
A)
B)
C)
D)
44
173)
173)
The AHRI definition of standard air is:
A)
0.75 lb/ft3 @ 75°F.
B)
.075 lb/ft2 @ 80°F.
C)
.075 ft3/lb. @ 95°F.
D)
.075 lb/ft3 @ 70°F.
Answer:
D
Explanation:
A)
B)
C)
D)
174)
174)
The substance that is used as the constant common material to measure specific gravity of solids
is:
A)
Water @ standard conditions.
B)
Air in a vacuum @ 29.9 in Hg.
C)
Ice @ standard conditions.
D)
Air at standard conditions.
Answer:
A
Explanation:
A)
B)
C)
D)
175)
175)
Evaporation occurs:
A)
Only above 212°F.
B)
Only above 100°F.
C)
Only on the surface of a liquid.
D)
Throughout the liquid above the boiling point.
Answer:
C
Explanation:
A)
B)
C)
D)
176)
176)
In contrast to liquids and vapors, solids will:
A)
Apply downward pressure when set on a surface.
B)
React to gravitational force.
C)
Apply pressure on the bottom and sides when contained.
D)
Apply pressure in all directions when set on a flat surface.
Answer:
A
Explanation:
A)
B)
C)
D)
45
177)
177)
What is the difference between the weight and mass of an object?
A)
Mass and weight both refer to the same physical property.
B)
Mass is not affected by gravity.
C)
Weight is not affected by gravity.
D)
Mass refers to an object's volume while weight measures the effect of gravity on an object.
Answer:
B
Explanation:
A)
B)
C)
D)
178)
178)
Specific gravity is defined as:
A)
The ratio of the density of a material as compared to a common material.
B)
The time element of inertia in which a specific amount of mass times the distance can be
moved.
C)
The force of gravity applied to a cubic foot of a mass.
D)
The ratio of mass per cubic foot acting upon a given mass.
Answer:
A
Explanation:
A)
B)
C)
D)
179)
179)
Which of the following is TRUE of items with a larger mass?
A)
Moving objects with more mass tend not to stay in motion.
B)
Objects with a larger mass have less inertia than objects with less mass.
C)
Heavier objects are easier to start moving than objects with less mass.
D)
Objects with a larger mass have more inertia than objects with less mass.
Answer:
D
Explanation:
A)
B)
C)
D)
180)
180)
The state of matter with the lowest energy level is:
A)
Solid.
B)
Gas.
C)
Liquid.
Answer:
A
Explanation:
A)
B)
C)
46
181)
181)
What is a practical use for knowing a substance's triple point?
A)
Calibrating thermometers using the triple point temperature
B)
Understanding that a system may not be charged past the triple point of the refrigerant
being used
C)
Understanding the practical operating limits of a refrigeration system
D)
Triple point is a purely theoretical concept that cannot be actually achieved
Answer:
A
Explanation:
A)
B)
C)
D)
182)
182)
Specific gravity is used in the HVACR industry:
A)
For recovering refrigerant.
B)
For charging air conditioners.
C)
For determining system capacity.
D)
For sizing gas lines.
Answer:
D
Explanation:
A)
B)
C)
D)
183)
183)
Which of the following is accurate about gases?
A)
Molecules of gases have a lower energy level than solids or liquids.
B)
Gases are not fluid.
C)
Gas has a fixed volume that will not change with temperature adjustments.
D)
A gas must be contained in a closed container or it will escape into the atmosphere.
Answer:
D
Explanation:
A)
B)
C)
D)
184)
184)
In the United States, the cooling capacity of air-conditioning equipment is expressed in:
A)
Calories.
B)
Tons.
C)
Therms.
D)
Joules.
Answer:
B
Explanation:
A)
B)
C)
D)
47
185)
185)
The unit used in the SI system for all forms of energy is:
A)
Therms.
B)
Horsepower.
C)
Joules.
D)
Watts.
Answer:
C
Explanation:
A)
B)
C)
D)
186)
186)
How many watts equal one horsepower of work?
A)
746 W = 1 hp
B)
1,000 W = 1 hp
C)
3,410 W = 1 hp
D)
1 W = 1 hp
Answer:
A
Explanation:
A)
B)
C)
D)
187)
187)
Coal, oil, and natural gas are all examples of:
A)
Perpetual energy sources.
B)
Low carbon energy sources.
C)
Nonrenewable energy sources.
D)
Renewable energy sources.
Answer:
C
Explanation:
A)
B)
C)
D)
188)
188)
Why is the number 3.41 significant in figuring BTU?
A)
One volt equals 3.41 BTU per hour.
B)
One BTU is produced every 3.41 hours.
C)
One watt produces 3.41 hp per hour.
D)
One watt produces 3.41 BTU per hour.
Answer:
D
Explanation:
A)
B)
C)
D)
48
189)
189)
How does natural gas move through pipelines from the well head to the end user thousands of
miles away?
A)
Large compressor pumping stations move the gas through the pipelines under high
pressure.
B)
Natural gas moves through the pipelines due to the extreme pressure on natural gas
underground.
C)
Natural gas moves naturally through the pipes because it is lighter than air.
D)
Solar energy is used to operate electric fans that help move the gas through the pipelines.
Answer:
A
Explanation:
A)
B)
C)
D)
190)
190)
Energy sources that cannot be replenished are called:
A)
Perpetual energy resources.
B)
Nonrenewable energy sources.
C)
Refillable energy sources.
D)
Renewable energy sources.
Answer:
B
Explanation:
A)
B)
C)
D)
191)
191)
Energy sources that can be replenished are called:
A)
Refillable energy sources.
B)
Nonrenewable energy sources.
C)
Perpetual energy resources.
D)
Renewable energy sources.
Answer:
D
Explanation:
A)
B)
C)
D)
192)
192)
A technician pushes a 50-lb box 4 feet in 2 seconds. The rate of work is:
A)
4 ft-lb.
B)
50 lb.
C)
50 lb × 4 ft = 200 ft-lb.
D)
200 ft-lb/2 s= 100 ft-lb/s.
Answer:
D
Explanation:
A)
B)
C)
D)
49
193)
193)
A waterfall is an example of:
A)
Cold fusion.
B)
Potential energy.
C)
Kinetic energy.
D)
Perpetual energy.
Answer:
C
Explanation:
A)
B)
C)
D)
194)
194)
If someone works with electricity, which of the following measurements may be used?
A)
Amperes and watts
B)
Foot-pounds and Newton meters
C)
Kilocalories and therms
D)
BTUs and calories
Answer:
A
Explanation:
A)
B)
C)
D)
195)
195)
Three forms of energy used in the heating and air conditioning include:
A)
Solid, liquid, and gas.
B)
Saturation, subcooling, superheat.
C)
Electrical, magnetic, mechanical.
D)
Preheat, setpoint, post heat.
Answer:
C
Explanation:
A)
B)
C)
D)
196)
196)
Electricity is the flow of:
A)
Electrons.
B)
Atoms.
C)
Protons.
D)
Neutrons.
Answer:
A
Explanation:
A)
B)
C)
D)
197)
197)
Molecules are composed of:
A)
Electrons and protons.
B)
Neutrons and protons.
C)
Atoms.
D)
Electrons, protons, and neutrons.
Answer:
C
Explanation:
A)
B)
C)
D)
50
198)
198)
Batteries are a good example of:
A)
Conversion of heat energy into mechanical energy.
B)
Conversion of mechanical energy into electrical energy.
C)
Conversion of chemical energy into electrical energy.
D)
Conversion of electrical energy into heat energy.
Answer:
C
Explanation:
A)
B)
C)
D)
199)
199)
How many BTUs will a 10-kW heater produce if operated for an hour?
A)
10 kW/3,410 BTU = 2.93 BTU
B)
10 kW 1 hour = 10,000 BTU
C)
10 kW × 1 hour × 3,410 BTU = 34,100 BTU
D)
(10 kW/3,410) × 60 = 176 BTU
Answer:
C
Explanation:
A)
B)
C)
D)
200)
200)
When an electron moves from one atom to another, it causes a chain reaction. What is the result of
this reaction?
A)
Radiant energy
B)
Chemical energy
C)
Thermal energy
D)
Electrical current
Answer:
D
Explanation:
A)
B)
C)
D)
201)
201)
A technician pushes a 50-lb box 4 feet in 2 seconds. The work done is:
A)
50 lb × 4 ft = 200 ft-lb.
B)
50 lb.
C)
4 ft-lb.
D)
200 ft-lb/2 s = 100 ft-lb/s.
Answer:
A
Explanation:
A)
B)
C)
D)
51
202)
202)
Torque is measured in:
A)
Watts.
B)
Pounds.
C)
Foot-pounds.
D)
Horsepower.
Answer:
C
Explanation:
A)
B)
C)
D)
203)
203)
When atoms join to make a new molecule:
A)
Energy is absorbed or released in the process.
B)
They become one large atom.
C)
The electrons and protons swap position.
D)
The nucleus of the larger atom absorbs the smaller atom.
Answer:
A
Explanation:
A)
B)
C)
D)
204)
204)
Common heat quantities arranged from smallest to largest are:
A)
Calorie, BTU, kilocalorie, therm.
B)
Therm, kilocalorie, joule, BTU.
C)
Therm, BTU, calorie, kilocalorie.
D)
BTU, calorie, kilocalorie, therm.
Answer:
A
Explanation:
A)
B)
C)
D)
205)
205)
Kinetic energy is:
A)
An energy source with promise that has not found practical application.
B)
Stored energy.
C)
Energy in motion.
D)
Purely theoretical.
Answer:
C
Explanation:
A)
B)
C)
D)
52
206)
206)
Which of the following is TRUE about the relationship between potential and kinetic energy?
A)
Kinetic and potential energy may be converted in either direction.
B)
Kinetic energy converts to potential energy, but not the reverse.
C)
Potential energy converts to kinetic energy, but not the reverse.
D)
There is no relationship between potential and kinetic energy.
Answer:
A
Explanation:
A)
B)
C)
D)
207)
207)
The rate of heat transfer is faster if:
A)
The two objects are exactly the same temperature.
B)
The molecular energy bands are in synchronous alignment.
C)
The temperatures of the two objects are very close to the same.
D)
There is a large temperature difference between the two objects.
Answer:
D
Explanation:
A)
B)
C)
D)
208)
208)
Electronic temperature sensors can be:
A)
Bimetal, mercury bulb, or piezoelectric.
B)
Thermistor, bimetal, or charged bulb.
C)
Generally less accurate than bimetal thermometers.
D)
Thermocouple, thermistor, or wire-wound.
Answer:
D
Explanation:
A)
B)
C)
D)
209)
209)
How many steps are required to calculate the heat necessary to change 10 lb of ice at -20°F to
steam at 250°F?
A)
Two
B)
Three
C)
Six
D)
One
Answer:
C
Explanation:
A)
B)
C)
D)
53
210)
210)
Calculate the amount of heat in BTU required to change the temperature of 10 lb of copper from
100°F to 150°F. The specific heat of copper is 0.09 BTU/lb.
A)
The amount of heat required cannot be calculated using the information given.
B)
10 lb × 50°F = 500 BTU
C)
10 lb × 50°F × 0.09 BTU/lb = 45 BTU
D)
10 lb × 0.09 BTU/lb = 0.9 BTU
Answer:
C
Explanation:
A)
B)
C)
D)
211)
211)
An air conditioner using refrigerant R-134a has a low-side pressure of 35 psig and a temperature
of 40°F. According to the pressure-temperature chart:
A)
It is saturated.
B)
It is superheated.
C)
It is subcooled.
D)
Its condition cannot be determined knowing just the pressure and temperature.
Answer:
A
Explanation:
A)
B)
C)
D)
212)
212)
According to the second law of thermodynamics, how does heat travel?
A)
Heat energy does not travel from one object to another.
B)
Heat energy travels to and from warmer objects.
C)
Heat energy travels from a warmer body to a cooler body.
D)
Heat energy travels from a cooler body to a warmer body.
Answer:
C
Explanation:
A)
B)
C)
D)
54
213)
213)
Natural convection occurs because of:
A)
Naturally occurring magnetic fields surrounding the earth.
B)
Fans, pumps, and other mechanical devices.
C)
Gentle breezes on properly placed equipment.
D)
Differences in fluid density due to temperature difference.
Answer:
D
Explanation:
A)
B)
C)
D)
214)
214)
Refrigerant in the evaporator coil of an air conditioner changes from a liquid to a gas when hot air
passes over it. The temperature of the refrigerant does not change. What concept does this
demonstrate?
A)
Radiation
B)
Specific heat
C)
Latent heat
D)
Convection
Answer:
C
Explanation:
A)
B)
C)
D)
215)
215)
The absolute temperature scale for Celsius is:
A)
Rankine.
B)
Celsius absolute.
C)
Kelvin.
D)
Fahrenheit.
Answer:
C
Explanation:
A)
B)
C)
D)
216)
216)
An air conditioner with refrigerant R-410a has a high-side pressure of 340 psig and a temperature
of 95°F. According to the pressure-temperature chart:
A)
It is saturated.
B)
It is superheated.
C)
It is subcooled.
D)
Its condition cannot be determined knowing just the pressure and temperature.
Answer:
C
Explanation:
A)
B)
C)
D)
55
217)
217)
What is the operating principle of glass stem thermometers?
A)
Expansion and contraction of the fluid makes the liquid level rise and fall with temperature.
B)
The refractive properties of the glass stem change with temperature, making the fluid level
appear higher at higher temperatures.
C)
The fluid climbs the walls of the tube through capillary attraction, which works better at
higher temperatures.
D)
The fluid inside the thermometer boils as it is heated, causing the liquid level to rise.
Answer:
A
Explanation:
A)
B)
C)
D)
218)
218)
The first law of thermodynamics states that:
A)
Whenever energy is created, an equal quantity of energy must be destroyed to maintain
thermal equilibrium.
B)
The molecular energy band is directly proportional to the thermal activity of the molecule.
C)
Energy cannot be created or destroyed.
D)
All objects contain some energy.
Answer:
C
Explanation:
A)
B)
C)
D)
219)
219)
Campers being heated by a fire outside are an example of:
A)
Conduction.
B)
Convection.
C)
Radiation.
D)
Sublimation.
Answer:
C
Explanation:
A)
B)
C)
D)
220)
220)
Convert -100° Celsius to Kelvin.
A)
-100 - 273 = - 373°K
B)
-100 + 460 = 360°K
C)
-100 + 273 = 173°K
D)
-100 - 460 = - 560°K
Answer:
C
Explanation:
A)
B)
C)
D)
56
221)
221)
How much heat is required to increase the temperature of 20 lb of water from 32°F to 212°F?
A)
212°F - 32°F = 180 BTU
B)
20 lb × 0.5 × 180°F = 1,800 BTU
C)
20 lb × 180°F = 3,600 BTU
D)
(20 × 144) + (20 × 180) + (20 × 970) = 25,880 BTU
Answer:
C
Explanation:
A)
B)
C)
D)
222)
222)
Which of the following changes occur in a melting ice cube?
A)
The water changes from a solid to a liquid.
B)
The water evaporates as it changes state.
C)
The increase in water temperature causes it to melt.
D)
The water increases in temperature as it melts.
Answer:
A
Explanation:
A)
B)
C)
D)
223)
223)
What happens to the temperature of water once it starts to boil?
A)
The water temperature stays the same once the water begins to boil.
B)
The water temperature decreases after the water begins to boil.
C)
It increases to 1°F above the boiling point.
D)
It increases above the boiling point in proportion to the amount of heat added during the
boiling process.
Answer:
A
Explanation:
A)
B)
C)
D)
224)
224)
One disadvantage of infrared thermometers is that they:
A)
Are generally less accurate than dial-type pocket thermometers.
B)
Take longer to get a reading than other types of thermometers.
C)
Can only read the temperature of objects.
D)
Are only available in limited quantities due to their specialized nature.
Answer:
C
Explanation:
A)
B)
C)
D)
57
225)
225)
What is the temperature of 125 Kelvin converted to Rankine?
A)
580 Rankine
B)
69.45 Rankine
C)
120 Rankine
D)
225 Rankine
Answer:
D
Explanation:
A)
B)
C)
D)
226)
226)
How do the freezing point of water and absolute zero compare?
A)
The freezing point of water is a higher temperature than absolute zero.
B)
The freezing point of water is a lower temperature than absolute zero.
C)
The freezing point of water and absolute zero are the same.
D)
Absolute zero is equal to the square root of the freezing point of water.
Answer:
A
Explanation:
A)
B)
C)
D)
227)
227)
The three basic methods of heat transfer are:
A)
Conduction, convection, and radiation.
B)
Specific, sensible, and latent.
C)
Anterior, inferior, and superior.
D)
Endothermal, exothermal, and isothermal.
Answer:
A
Explanation:
A)
B)
C)
D)
228)
228)
Vacuum is often measured in:
A)
Inches of alcohol.
B)
Kilopascals.
C)
Inches of mercury.
D)
Pounds of vacuum.
Answer:
C
Explanation:
A)
B)
C)
D)
58
229)
229)
If the head of a body of fluid increases, which of the following happens to the pressure and depth?
A)
The pressure and depth decrease.
B)
The pressure decreases, but the depth increases.
C)
The pressure is unaffected, but the depth increases.
D)
The pressure and depth increase.
Answer:
D
Explanation:
A)
B)
C)
D)
230)
230)
What is the head pressure of a tank 10 ft in height?
A)
4.33 psi
B)
433 psi
C)
0.433 psi
D)
43.3 psi
Answer:
A
Explanation:
A)
B)
C)
D)
231)
231)
When the current atmospheric pressure is not considered in measuring pressure, it is known as:
A)
Column pressure.
B)
Internal pressure.
C)
Gauge pressure.
D)
Absolute pressure.
Answer:
D
Explanation:
A)
B)
C)
D)
232)
232)
The definition of a fluid is:
A)
A substance that deforms and flows under pressure.
B)
Any substance in liquid form.
C)
Any liquid which cannot become a vapor at system pressure and temperature.
D)
A liquid with a viscosity equal to or greater than the ANSI requirement for standard fluid.
Answer:
A
Explanation:
A)
B)
C)
D)
59
233)
233)
Atmospheric pressure is created by:
A)
There is no such thing as atmospheric pressure.
B)
Centrifugal force created by the spinning of the earth.
C)
The weight of the air in the atmosphere.
D)
The earth's magnetic field.
Answer:
C
Explanation:
A)
B)
C)
D)
234)
234)
HVACR technicians use tools that compare pressure to atmospheric pressure. What is this type of
pressure called?
A)
Column pressure
B)
Barometric pressure
C)
Gauge pressure
D)
Absolute pressure
Answer:
C
Explanation:
A)
B)
C)
D)
235)
235)
After heating a fixed volume of gas at 50 psia from 300° R to 600°R, its pressure will be:
A)
25 psia because the pressure and temperature vary inversely.
B)
The final pressure cannot be determined without knowing the volume.
C)
100 psia because the pressure and temperature vary directly.
D)
50 psia because pressure and temperature are independent variables.
Answer:
C
Explanation:
A)
B)
C)
D)
236)
After heating 2 ft3 of gas at 50 psia from 300° R to 600°R at 50 psia, the volume of the gas will be:
236)
A)
4 ft3 because the volume and temperature vary directly.
B)
The final volume cannot be determined without knowing the specific gravity of the gas.
C)
2 ft3 because the pressure did not change.
D)
1 ft3 because the temperature and volume vary inversely.
Answer:
A
Explanation:
A)
B)
C)
D)
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