314)
314)
Gravity causes liquids to exert force:
A)
Downward.
B)
In all directions.
C)
Downward and to the sides.
D)
Liquids do not exert force.
Answer:
C
Explanation:
A)
B)
C)
D)
315)
315)
When the performances of systems are analyzed, it is necessary to:
A)
Analyze the systems at the same time of day to ensure an accurate analysis.
B)
Analyze the systems the same amount of time to ensure an accurate analysis.
C)
Analyze the systems under the same conditions to ensure an accurate analysis.
D)
Analyze the systems at the same location to ensure an accurate analysis.
Answer:
C
Explanation:
A)
B)
C)
D)
316)
316)
The pressure and temperature at which there is no longer a difference between liquid and gas is
called:
A)
Point of saturation.
B)
Point of vaporization.
C)
Critical point.
D)
Critical mass.
Answer:
C
Explanation:
A)
B)
C)
D)
317)
317)
Gravity causes solids to exert force:
A)
In all directions.
B)
Downward and to the sides.
C)
Downward.
D)
A solid does not exert force.
Answer:
C
Explanation:
A)
B)
C)
D)
81
318)
318)
The substance used to compare the specific gravity of liquids is:
A)
Ozone.
B)
Water.
C)
Air.
D)
Carbon dioxide.
Answer:
B
Explanation:
A)
B)
C)
D)
319)
319)
Specific volume can be described using which of the following units?
A)
Pounds per square foot
B)
Ounces per cubic inch
C)
Pounds per cubic foot
D)
Cubic feet per pound
Answer:
D
Explanation:
A)
B)
C)
D)
320)
320)
The freezing point of substances:
A)
Is the change of state of a substance from a liquid to a solid at a given pressure and
temperature when heat is removed.
B)
Is 32°C.
C)
Is 0°F.
D)
Never considers pressures or temperatures.
Answer:
A
Explanation:
A)
B)
C)
D)
321)
321)
A metal rod is heated on one end and heat travels from that end to the cooler end through the rod.
This is an example of:
A)
Conduction.
B)
Convection.
C)
Radiation.
D)
Sublimation.
Answer:
A
Explanation:
A)
B)
C)
D)
82
322)
322)
What is the first color of visible light that is given off by heated objects as they increase in
temperature?
A)
Blue
B)
Violet
C)
Red
D)
Yellow
Answer:
C
Explanation:
A)
B)
C)
D)
323)
323)
According to Joe’s pressure–temperature chart, the saturation temperature for 12 lb of pressure is
36.9°F. The actual refrigerant temperature measured was 35.2°F. What does this tell you about the
refrigerant?
A)
It is saturated.
B)
It is supercooled.
C)
It is superheated.
D)
It is subcooled.
Answer:
A
Explanation:
A)
B)
C)
D)
324)
324)
The air circulating inside a refrigerator is an example of:
A)
Conduction.
B)
Convection.
C)
Radiation.
D)
Sublimation.
Answer:
B
Explanation:
A)
B)
C)
D)
325)
325)
Calculate the amount of heat required to change 5 lb of 32°F ice to water.
A)
5 lb × 32°F × 0.5 BTU/lb = 80 BTU
B)
No extra heat is required because the ice is already at the melting temperature.
C)
5 lb × 144 BTU/lb = 720 BTU
D)
The amount of heat required cannot be calculated without knowing the ending temperature
of the water.
Answer:
C
Explanation:
A)
B)
C)
D)
83
326)
326)
What is an absolute temperature scale?
A)
A thermometer that has been NIST calibrated to be absolutely correct
B)
A temperature scale that uses sensitive wireless sensors to detect the vibrational frequency
of the molecules in a substance to determine its temperature to a high degree of accuracy
C)
A theoretical temperature scale that only applies to quantum physics
D)
A temperature scale with no negative temperatures and 0° equal to absolute zero
Answer:
D
Explanation:
A)
B)
C)
D)
327)
327)
What is absolute zero?
A)
The theoretical starting temperature for quantum physics experiments which is derived by
measuring the average rotational velocity of the molecules
B)
The coldest temperature possible where all molecular motion stops
C)
The hottest possible temperature where matter is indistinguishable from energy
D)
The freezing point of water on an absolute temperature scale
Answer:
B
Explanation:
A)
B)
C)
D)
328)
328)
Convert 200° Rankine to Kelvin.
A)
200 + 273 = 473°K
B)
200 × 1.8 = 360°K
C)
200/1.8 = 111.11°K
D)
200 + 460 = 660°K
Answer:
C
Explanation:
A)
B)
C)
D)
329)
329)
Most materials that are good electrical conductors:
A)
Will transfer heat by convection, but not by conduction.
B)
Will transfer heat by radiation, but not by conduction.
C)
Also tend to make good thermal conductors.
D)
Are poor thermal conductors.
Answer:
C
Explanation:
A)
B)
C)
D)
84
330)
330)
An air conditioner with refrigerant R–22 has a low–side pressure of 70 psig and a temperature of
55°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:
B
Explanation:
A)
B)
C)
D)
331)
331)
How does additional pressure that is applied to a high–pressure gauge register when connected to
a piece of equipment?
A)
The Bourdon tube rotates to indicate a change in pressure.
B)
The Bourdon tube straightens out and moves the needle to indicate pressure.
C)
The fluid in the Bourdon tube moves to a higher position to indicate pressure.
D)
The Bourdon tube flattens out when the mechanical needle to shows pressure.
Answer:
B
Explanation:
A)
B)
C)
D)
332)
332)
A pressure of 1 bar is approximately equal to:
A)
14.7 psig.
B)
1000 kilopascals.
C)
The pressure exerted by a 1–kilogram bar over a 1–square–meter surface.
D)
Atmospheric pressure.
Answer:
D
Explanation:
A)
B)
C)
D)
85
333)
333)
A refrigerant properties chart calls for 100 psia. The reading you would see on your gauges is:
A)
100 psia – 15 = 85 psig (rounded).
B)
100 psia + 15 = 115 psig (rounded).
C)
100 psig.
D)
The pressure reading cannot be determined without knowing the refrigerant.
Answer:
A
Explanation:
A)
B)
C)
D)
334)
334)
A barometer is used to read:
A)
Relative humidity.
B)
System pressures.
C)
Wind speed.
D)
Atmospheric pressure.
Answer:
D
Explanation:
A)
B)
C)
D)
335)
335)
What kinds of pressures are expressed in inches of water column?
A)
Air pressure in ductwork or gas line pressure
B)
Atmospheric pressure or vacuum
C)
Saturation pressures on a saturation pressure–temperature chart
D)
Refrigeration system high– and low–side pressures
Answer:
A
Explanation:
A)
B)
C)
D)
336)
336)
The curved oval metal tube inside a gauge is called:
A)
A pressure tube.
B)
A strain gauge.
C)
A Bourdon tube.
D)
A pressure transducer.
Answer:
C
Explanation:
A)
B)
C)
D)
86
337)
337)
Convert 55 psig to absolute pressure.
A)
55 psig – 30 = 25 psia (rounded)
B)
55 psig + 30 = 85 psia (rounded)
C)
55 psig + 15 = 70 psia (rounded)
D)
55 psig – 15 = 40 psia (rounded)
Answer:
C
Explanation:
A)
B)
C)
D)
338)
338)
Density is defined as:
A)
The volume at standard conditions.
B)
Weight divided by volume.
C)
The weight at standard conditions.
D)
Volume divided by weight.
Answer:
B
Explanation:
A)
B)
C)
D)
339)
339)
When working in the refrigeration and air–conditioning industry, matter is typically encountered
in three states:
A)
Solid, liquid, vapor.
B)
Chemical, plasma, electrical.
C)
Animal, vegetable, mineral.
D)
Fahrenheit, Celsius, Kelvin.
Answer:
A
Explanation:
A)
B)
C)
D)
340)
340)
Matter is defined as:
A)
Anything that has mass and takes up space.
B)
Physical objects that can be seen.
C)
Physical objects that emit energy.
D)
Anything that has weight, can be seen, and emits energy.
Answer:
A
Explanation:
A)
B)
C)
D)
87
341)
341)
The AHRI definition of standard air is:
A)
400 CFM per ton.
B)
Air weighing 0.075 lb/ft3 at 70°F with a barometric pressure of 29.92 in Hg.
C)
78% nitrogen, 21% oxygen, and 1% “other” gases.
D)
Air at a temperature of 0°C with a relative humidity of 50%.
Answer:
B
Explanation:
A)
B)
C)
D)
342)
342)
The wet bulb temperature for AHRI rating condition “A” is:
A)
75°F.
B)
78°F.
C)
67°F.
D)
70°F.
Answer:
C
Explanation:
A)
B)
C)
D)
343)
343)
Gravity causes gases to exert force:
A)
In all directions.
B)
Downward.
C)
Downward and to the sides.
D)
Gases do not exert force.
Answer:
A
Explanation:
A)
B)
C)
D)
344)
344)
In physics, solids and liquids:
A)
Do not change in volume when pressures change, but gases will change.
B)
Change when critical pressure is applied to the mass.
C)
Will occupy the same amount of space given the temperature is below 212°F.
D)
Change in volume when critical temperature is applied to the mass.
Answer:
A
Explanation:
A)
B)
C)
D)
88
345)
345)
What physical change of state is the opposite of deposition?
A)
Freezing
B)
Sublimation
C)
Condensation
D)
Melting
Answer:
B
Explanation:
A)
B)
C)
D)
346)
346)
What temperature scale uses 32° as the freezing point of water and 212° as the boiling point of
water?
A)
Kelvin
B)
Celsius
C)
Fahrenheit
D)
Rankine
Answer:
C
Explanation:
A)
B)
C)
D)
347)
347)
As the distance between two objects increases, the radiant energy transferred between them:
A)
Decreases.
B)
Stays the same.
C)
Oscillates.
D)
Increases.
Answer:
A
Explanation:
A)
B)
C)
D)
348)
348)
What is a k factor?
A)
A measure of specific heat capacity in BTU/lb
B)
A measure of heat content in BTU/lb
C)
A measure of thermal resistance in BTU/hr/ft2/°F/in of thickness
D)
A measure of thermal conductivity in BTU/hr/ft2/°F/in of thickness
Answer:
D
Explanation:
A)
B)
C)
D)
89
349)
349)
Which is TRUE of absolute temperature?
A)
Discovering the starting point of temperature required mathematical calculations.
B)
Discovering the end point of temperature required complex calculations.
C)
The reference points in traditional scales were useful in absolute temperature calculations.
D)
There is no start or end point to temperature.
Answer:
A
Explanation:
A)
B)
C)
D)
350)
350)
Which of the following is an example of forced convection?
A)
Air moving in a refrigerator
B)
Heat traveling along a metal rod
C)
A radiant heater placed in a room
D)
A ceiling fan forcing warm air down
Answer:
D
Explanation:
A)
B)
C)
D)
351)
351)
Two materials that are considered good thermal conductors are:
A)
Paper and wood.
B)
Thermoplastic and rubber.
C)
Copper and aluminum.
D)
Glass and ceramic.
Answer:
C
Explanation:
A)
B)
C)
D)
352)
352)
The pointer on a dial–type thermometer is moved by a:
A)
Heat motor and gears.
B)
Bimetal element.
C)
Lever that is moved by a column of mercury.
D)
Volatile fluid.
Answer:
B
Explanation:
A)
B)
C)
D)
90
353)
353)
The nucleus of an atom:
A)
Is negatively charged.
B)
Is composed of protons and neutrons.
C)
Produces centrifugal force.
D)
Has a neutral charge.
Answer:
B
Explanation:
A)
B)
C)
D)
354)
354)
When a liquid–vapor mix is heated in a closed space, eventually the density of the liquid
decreases and the density of the gas increases. When no difference between the liquid and vapor
exists, it has reached its:
A)
Triple point.
B)
Critical point.
C)
Thermal equilibrium.
D)
Critical mass.
Answer:
B
Explanation:
A)
B)
C)
D)
355)
355)
The volume of a solid will:
A)
Increase significantly as the temperature of the solid increases.
B)
Change very little when temperature changes occur.
C)
Decrease when the temperature increases.
D)
Increase as the temperature decreases.
Answer:
B
Explanation:
A)
B)
C)
D)
356)
356)
Elements are:
A)
The forces of velocity pressure and density upon a substance.
B)
Pressure and temperature.
C)
Naturally occurring chemicals.
D)
Force and pressure.
Answer:
C
Explanation:
A)
B)
C)
D)
91
357)
357)
Which of the following statements are TRUE for matter in a gas state?
A)
Gas has a definite volume.
B)
Gas has a definite shape.
C)
Gas is the lowest energy level of all states of matter.
D)
Gas will exert equal pressure on all sides when inside a closed container.
Answer:
D
Explanation:
A)
B)
C)
D)
358)
358)
The reason thermal properties of matter are important is because:
A)
They determine which direction vortexes will form through a restriction.
B)
Heating and air conditioning are about moving heat.
C)
They determine the relative buoyancy of two liquids at a constant temperature.
D)
They determine if something is wood or metal.
Answer:
B
Explanation:
A)
B)
C)
D)
359)
359)
The Rankine temperature scale is:
A)
The absolute temperature scale for Kelvin.
B)
The most common temperature scale used in medicine.
C)
The absolute temperature scale for Fahrenheit.
D)
The absolute temperature scale for Celsius.
Answer:
C
Explanation:
A)
B)
C)
D)
360)
360)
The absolute temperature scale for Fahrenheit is:
A)
Fahrenheit absolute.
B)
Kelvin.
C)
Rankine.
D)
Celsius.
Answer:
C
Explanation:
A)
B)
C)
D)
92
361)
361)
A heat process that causes a change in a substance’s temperature is called:
A)
Latent heat.
B)
Sensible heat.
C)
Specific heat capacity.
D)
Total heat.
Answer:
B
Explanation:
A)
B)
C)
D)
362)
362)
Which type of thermometer can measure the temperature of a surface from a distance?
A)
Dial–type bimetal thermometers
B)
Digital pocket thermometers
C)
Glass stem thermometers
D)
Infrared
Answer:
D
Explanation:
A)
B)
C)
D)
363)
363)
What measurements are needed to determine if refrigerant in a refrigeration system is saturated,
superheated, or subcooled?
A)
Enthalpy differential measurements
B)
An accurate measurement of heat
C)
Accurate pressure and temperature readings
D)
A manometer and a sling psychrometer
Answer:
C
Explanation:
A)
B)
C)
D)
364)
364)
The two metals used in a type K thermocouple are:
A)
Aluminum and copper.
B)
Iron and steel.
C)
Copper and antimony.
D)
Chromel and alumel.
Answer:
D
Explanation:
A)
B)
C)
D)
93
365)
365)
A thorough knowledge of the properties of matter is necessary to:
A)
Know where to locate the heating or cooling equipment and system in a building structure.
B)
Design air–conditioning equipment and systems for a building structure.
C)
Better understand what happens to various forms of matter and the reasons why changes
occur when substances are heated or cooled.
D)
Explain to a customer what type of heating or cooling system is needed to accommodate the
building load requirements.
Answer:
C
Explanation:
A)
B)
C)
D)
366)
366)
How would the law of conservation of matter explain what happens to a cup of water when it
evaporates?
A)
The evaporation process destroys the water in the cup.
B)
The liquid water is now water vapor of the same quantity.
C)
The liquid water becomes a larger quantity of water vapor.
D)
The water in the cup becomes a smaller amount of water vapor.
Answer:
B
Explanation:
A)
B)
C)
D)
367)
367)
The triple point of a substance is:
A)
That point when the substance changes its specific gravity at the same pressure,
temperature, and volume.
B)
The point where a substance can exist as a solid, liquid, or vapor at the same time at one
specific pressure and temperature.
C)
The point at which the substance changes state at the same pressure, temperature, and
volume.
D)
The point when the density of a substance changes to a solid, liquid, or vapor at standard
conditions.
Answer:
B
Explanation:
A)
B)
C)
D)
94
368)
368)
When a vapor condenses:
A)
The potential energy inside the molecules decreases.
B)
The molecular motion of its atoms increases.
C)
The amount of energy inside the molecules increases.
D)
The molecular motion of the atoms ceases.
Answer:
A
Explanation:
A)
B)
C)
D)
369)
369)
The state of matter with the highest energy level is:
A)
Solid.
B)
Gas.
C)
Liquid.
Answer:
B
Explanation:
A)
B)
C)
370)
370)
Which of the following forms of heat travels in waves?
A)
Sensible heat
B)
Specific heat
C)
All forms of heat
D)
Radiant heat
Answer:
D
Explanation:
A)
B)
C)
D)
371)
371)
Convert 40° Fahrenheit to Celsius.
A)
40 – 32 = 8; 8 × 1.8 = 9.6°C
B)
40/1.8 = 22.2; 22.2 – 32 = – 10°C
C)
40 – 32 = 8; 8/1.8 = 4.4°C
D)
40 + 40 = 80; 80 × 1.8 = 144; 144 – 40 = 104°C
Answer:
C
Explanation:
A)
B)
C)
D)
95
372)
372)
The relationship between Celsius and Fahrenheit is that:
A)
There are 1.8 Fahrenheit degrees for every Celsius degree.
B)
Celsius temperatures are generally higher than Fahrenheit temperatures.
C)
0°C is equal to 0°F.
D)
There are 1.8 Celsius degrees for every Fahrenheit degree.
Answer:
A
Explanation:
A)
B)
C)
D)
373)
373)
Convert 100° Rankine to Fahrenheit.
A)
100 + 460 = 560°F
B)
100 – 273 = – 173°F
C)
100 + 273 = 373°F
D)
100 – 460 = – 360°F
Answer:
D
Explanation:
A)
B)
C)
D)
374)
374)
If molecules in substance A are moving at a higher rate than the molecules in substance B,which
substance has the higher temperature?
A)
Substance A
B)
Molecular motion is not associated with temperature.
C)
They are the same temperature.
D)
Substance B
Answer:
A
Explanation:
A)
B)
C)
D)
96
375)
375)
Which basic principle is one that influences how all HVACR systems work?
A)
Pressure affects boiling point and evaporation in an unpredictable way, so it must not be
considered in HVACR equipment.
B)
A decrease in pressure increases the boiling point of liquid, the temperature at which a
liquid turns to a gas.
C)
An increase in pressure can lower the boiling point of a liquid and change the temperature
at which it turns to a gas.
D)
An increase in pressure can increase the boiling point of a liquid, the temperature at which a
liquid turns to a gas.
Answer:
D
Explanation:
A)
B)
C)
D)
376)
376)
Liquid molecules have ________ level of energy than matter in a solid state.
A)
a lower
B)
an equal
C)
an undetermined
D)
a higher
Answer:
D
Explanation:
A)
B)
C)
D)
377)
377)
If an HVACR technician determines the ratio of the density of a material to the density of a
common material, what is she calculating?
A)
Density
B)
Volume
C)
Specific gravity
D)
Specific volume
Answer:
C
Explanation:
A)
B)
C)
D)
378)
378)
A molecule is:
A)
The smallest part of a substance that is not an element.
B)
The smallest parts of an atom.
C)
Composed of photons and protons.
D)
Composed of protons and neutrinos.
Answer:
A
Explanation:
A)
B)
C)
D)
97
379)
379)
Temperature is the measure of:
A)
The average potential energy in a substance.
B)
The average amount of heat in a substance.
C)
The average kinetic energy in a substance.
D)
The total amount of heat in a substance.
Answer:
C
Explanation:
A)
B)
C)
D)
380)
380)
A heat process that causes a substance to change state is called:
A)
Latent heat.
B)
Sensible heat.
C)
Specific heat capacity.
D)
Total heat.
Answer:
A
Explanation:
A)
B)
C)
D)
381)
381)
Convert –100° Fahrenheit to Rankine.
A)
–100 + 460 = 360°R
B)
–100 – 460 = – 560°R
C)
–100 – 273 = – 373°R
D)
–100 + 273 = 173°R
Answer:
A
Explanation:
A)
B)
C)
D)
382)
382)
Select the temperature scales that can be used to work gas law problems. You may select more
than one.
A)
Rankine
B)
Fahrenheit
C)
Celsius
D)
Kelvin
Answer:
A, D
Explanation:
A)
B)
C)
D)
98
383)
383)
Freezer burn occurs when water slowly exits perishable foods during the freezing process. This
process is known as: (SERVICE TIP)
A)
Latent change of state.
B)
Deposition.
C)
Sublimation.
D)
Deterioration.
Answer:
C
Explanation:
A)
B)
C)
D)
384)
384)
The energy change that takes place when the atoms of materials are rearranged to form new
materials from the same atoms is:
A)
The energy of centripetal force.
B)
The energy of centrifugal force.
C)
Kinetic energy.
D)
Chemical energy.
Answer:
D
Explanation:
A)
B)
C)
D)
385)
385)
The triple point of most substances is:
A)
Greater than atmospheric pressure.
B)
Always measured when a substance is in a closed container.
C)
Less than atmospheric pressure.
D)
Dependent upon barometric pressure above atmospheric and ambient temperatures above
70°F.
Answer:
C
Explanation:
A)
B)
C)
D)
386)
386)
A correct statement concerning inertia is:
A)
All objects are put into motion by the same amount of force regardless of the quantity of
mass.
B)
When dropped from the same height, all objects will hit the ground at the same time
regardless of their weight.
C)
All objects that are at rest have the tendency to stay at rest and when in motion tend to stay
in motion.
D)
Synonymous with kinetic energy.
Answer:
C
Explanation:
A)
B)
C)
D)
99
387)
387)
The three states of matter represent:
A)
The levels of chemical energy, photovoltaic energy, and radiation within a substance.
B)
Total velocity pressure, static pressure, molecular pressure.
C)
Diverse levels of molecular energy within a material or substance.
D)
The amount of work a material can accomplish.
Answer:
C
Explanation:
A)
B)
C)
D)
388)
388)
The volume of ________ is subject to the greatest amount of change when there is a change of
pressure and temperature.
A)
a solid
B)
a gas
C)
a liquid
D)
a condensate
Answer:
B
Explanation:
A)
B)
C)
D)
389)
389)
The state in which a substance exists depends on:
A)
Pressure and temperature.
B)
The critical point.
C)
Temperature at standard conditions.
D)
Pressure at standard conditions.
Answer:
A
Explanation:
A)
B)
C)
D)
390)
390)
It is important to the HVACR technician to understand the changes of state of matter because:
A)
Technicians are required to mix refrigerants to attain proper pressures and temperatures
when charging refrigeration systems.
B)
NATE certification exams require a good understanding of the periodic table of elements.
C)
The cooling and heating process requires a change of state of matter in some form.
D)
The refrigerant recovery process requires a technician to know which state the matter is in
to ensure that only like refrigerants are put into a recovery container.
Answer:
C
Explanation:
A)
B)
C)
D)
100