Chapter 18 - Temperature, Heat, and The First Law of Thermodynamics
Chapter 18 - Temperature, Heat, and The First Law of Thermodynamics
Chapter 18 - Temperature, Heat, and The First Law of Thermodynamics
270
6. If the zeroth law of thermodynamics were not valid, which of the following could not be considered a property of an object?
A. Pressure
B. Center of mass energy
C. Internal energy
D. Momentum
E. Temperature
ans: E
7. The international standard thermometer is kept:
A. near Washington, D.C.
B. near Paris, France
C. near the north pole
D. near Rome, Italy
E. nowhere (there is none)
ans: E
8. In constructing a thermometer it is NECESSARY to use a substance that:
A. expands with rising temperature
B. expands linearly with rising temperature
C. will not freeze
D. will not boil
E. undergoes some change when heated or cooled
ans: E
9. The triple point of a substance is that point for which the temperature and pressure are such
that:
A. only solid and liquid are in equilibrium
B. only liquid and vapor are in equilibrium
C. only solid and vapor are in equilibrium
D. solid, liquid, and vapor are all in equilibrium
E. the temperature, pressure and density are all numerically equal
ans: D
10. Constant-volume gas thermometers using dierent gases all indicate nearly the same temperature when in contact with the same object if:
A. the volumes are all extremely large
B. the volumes are all the same
D. the pressures are all extremely large
C. the pressures are the same
E. the particle concentrations are all extremely small
ans: E
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11. A constant-volume gas thermometer is used to measure the temperature of an object. When
the thermometer is in contact with water at its triple point (273.16 K) the pressure in the
thermometer is 8.500 104 Pa. When it is in contact with the object the pressure is 9.650
104 Pa. The temperature of the object is:
A. 37.0 K
B. 241 K
C. 310 K
D. 314 K
E. 2020 K
ans: C
12. When a certain constant-volume gas thermometer is in thermal contact with water at its triple
point (273.16 K) the pressure is 6.30 104 Pa. For this thermometer a kelvin corresponds to a
change in pressure of about:
A. 4.34 102 Pa
B. 2.31 102 Pa
C. 1.72 103 Pa
D. 2.31 103 Pa
E. 1.72 107 Pa
ans: B
13. The diagram shows four thermometers, labeled W, X, Y, and Z. The freezing and boiling points
of water are indicated. Rank the thermometers according to the size of a degree on their scales,
smallest to largest.
A.
B.
C.
D.
E.
100
125
175
75
45
55
35
boiling point
freezing point
W, X, Y, Z
Z, Y, X, W
Z, Y, W, X
Z, X, W, Y
W, Y, Z, X
ans: D
14. There is a temperature at which the reading on the Kelvin scale is numerically:
A. equal to that on the Celsius scale
B. lower than that on the Celsius scale
C. equal to that on the Fahrenheit scale
D. less than zero
E. none of the above
ans: C
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273
274
25. The gure shows a rectangular brass plate at 0 C in which there is cut a rectangular hole of
dimensions indicated. If the temperature of the plate is raised to 150 C:
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26. The Stanford linear accelerator contains hundreds of brass disks tightly tted into a steel tube
(see gure). The coe cient of linear expansion of the brass is 2.00 105 per C . The system
was assembled by cooling the disks in dry ice (57 C) to enable them to just slide into the
close-tting tube. If the diameter of a disk is 80.00 mm at 43 C, what is its diameter in the
dry ice?
...............................
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brass disk
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steel tube
A.
B.
C.
D.
E.
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78.40 mm
79.68 mm
80.16 mm
79.84 mm
None of these
ans: D
27. When the temperature of a copper penny is increased by 100 C, its diameter increases by
0.17%. The area of one of its faces increases by:
A. 0.17%
B. 0.34%
C. 0.51%
D. 0.13%
E. 0.27%
ans: B
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28. An annular ring of aluminum is cut from an aluminum sheet as shown. When this ring is
heated:
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A.
B.
C.
D.
E.
the aluminum expands outward and the hole remains the same in size
the hole decreases in diameter
the area of the hole expands the same percent as any area of the aluminum
the area of the hole expands a greater percent than any area of the aluminum
linear expansion forces the shape of the hole to be slightly elliptical
ans: C
29. Possible units for the coe cient of volume expansion are:
A. mm/C
B. mm3 /C
C. (C )3
D. 1/(C )3
E. 1/C
ans: E
30. The mercury column in an ordinary medical thermometer doubles in length when its temperature changes from 95 F to 105 F. Choose the correct statement:
A. the coe cient of volume expansion of mercury is 0.1 per F
B. the coe cient of volume expansion of mercury is 0.3 per F
C. the coe cient of volume expansion of mercury is (0.1/3) per F
D. the vacuum above the column helps to pull up the mercury this large amount
E. none of the above is true
ans: E
31. The coe cient of linear expansion of iron is 1.0 105 per C . The surface area of an iron
cube, with an edge length of 5.0 cm, will increase by what amount if it is heated from 10 C to
60 C?
A. 0.0125 cm2
B. 0.025 cm2
C. 0.075 cm2
D. 0.15 cm2
E. 0.30 cm2
ans: D
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32. The diagram shows four rectangular plates and their dimensions. All are made of the same
material. The temperature now increases. Of these plates:
L
2L
L
L
1
A. the vertical
most
B. the vertical
most
C. the vertical
most
D. the vertical
most
E. the vertical
most
ans: D
3L
2L
2L
L
dimension of plate 1 increases the most and the area of plate 1 increases the
dimension of plate 2 increases the most and the area of plate 4 increases the
dimension of plate 3 increases the most and the area of plate 1 increases the
dimension of plate 4 increases the most and the area of plate 3 increases the
dimension of plate 4 increases the most and the area of plate 4 increases the
33. The coe cient of linear expansion of steel is 11 106 per C . A steel ball has a volume of
exactly 100 cm3 at 0 C. When heated to 100 C, its volume becomes:
A. 100.33 cm3
B. 100.0011 cm3
C. 100.0033 cm3
D. 100.000011 cm3
E. none of these
ans: A
34. The coe cient of linear expansion of a certain steel is 0.000012 per C . The coe cient of
volume expansion, in (C )1 , is:
A. (0.000012)3
B. (4 /3)(0.000012)3
C. 3 0.000012
D. 0.000012
E. depends on the shape of the volume to which it will be applied
ans: C
35. Metal pipes, used to carry water, sometimes burst in the winter because:
A. metal contracts more than water
B. outside of the pipe contracts more than the inside
C. metal becomes brittle when cold
D. ice expands when it melts
E. water expands when it freezes
ans: E
Chapter 18: TEMPERATURE, HEAT, AND THE FIRST LAW OF THERMODYNAMICS
277
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279
46. A cube of aluminum has an edge length of 20 cm. Aluminum has a density 2.7 times that of
3
water (1 g/cm ) and a specic heat 0.217 times that of water (1 cal/g C ). When the internal
energy of the cube increases by 47000 cal its temperature increases by:
A. 5 C
B. 10 C
C. 20 C
D. 100 C
E. 200 C
ans: B
47. An insulated container, lled with water, contains a thermometer and a paddle wheel. The
paddle wheel can be rotated by an external source. This apparatus can be used to determine:
A. specic heat of water
B. relation between kinetic energy and absolute temperature
C. thermal conductivity of water
D. e ciency of changing work into heat
E. mechanical equivalent of heat
ans: E
48. Take the mechanical equivalent of heat as 4 J/cal. A 10-g bullet moving at 2000 m/s plunges
into 1 kg of para n wax (specic heat 0.7 cal/g C ). The wax was initially at 20 C. Assuming
that all the bullets energy heats the wax, its nal temperature (in C) is:
A. 20.14
B. 23.5
C. 20.006
D. 27.1
E. 30.23
ans: D
49. The energy given o as heat by 300 g of an alloy as it cools through 50 C raises the temperature
of 300 g of water from 30 C to 40 C. The specic heat of the alloy (in cal/g C ) is:
A. 0.015
B. 0.10
C. 0.15
D. 0.20
E. 0.50
ans: D
50. The specic heat of lead is 0.030 cal/g C . 300 g of lead shot at 100 C is mixed with 100 g of
water at 70 C in an insulated container. The nal temperature of the mixture is:
A. 100 C
B. 85.5 C
C. 79.5 C
D. 74.5 C
E. 72.5 C
ans: E
280
51. Object A, with heat capacity CA and initially at temperature TA , is placed in thermal contact
with object B, with heat capacity CB and initially at temperature TB . The combination is
thermally isolated. If the heat capacities are independent of the temperature and no phase
changes occur, the nal temperature of both objects is:
A. (CA TA CB TB )/(CA + CB )
B. (CA TA + CB TB )/(CA + CB )
C. (CA TA CB TB )/(CA CB )
D. (CA CB )|TA TB |
E. (CA + CB )|TA TB |
ans: B
52. The heat capacity of object B is twice that of object A. Initially A is at 300 K and B is at 450 K.
They are placed in thermal contact and the combination is isolated. The nal temperature of
both objects is:
A. 200 K
B. 300 K
C. 400 K
D. 450 K
E. 600 K
ans: C
53. A heat of transformation of a substance is:
A. the energy absorbed as heat during a phase transformation
B. the energy per unit mass absorbed as heat during a phase transformation
C. the same as the heat capacity
D. the same as the specic heat
E. the same as the molar specic heat
ans: B
54. The heat of fusion of water is cal/g. This means 80 cal of energy are required to:
A. raise the temperature of 1 g of water by 1 K
B. turn 1 g of water to steam
C. raise the temperature of 1 g of ice by 1 K
D. melt 1 g of ice
E. increase the internal energy of 80 g of water by 1 cal
ans: D
55. Solid A, with mass M , is at its melting point TA . It is placed in thermal contact with solid
B, with heat capacity CB and initially at temperature TB (TB > TA ). The combination is
thermally isolated. A has latent heat of fusion L and when it has melted has heat capacity CA .
If A completely melts the nal temperature of both A and B is:
A. (CA TA + CB TB M L)/(CA + CB )
B. (CA TA CB TB + M L)/(CA + CB )
C. (CA TA CB TB M L)/(CA + CB )
D. (CA TA + CB TB + M L)/(CA CB )
E. (CA TA + CB TB + M L)/(CA CB )
ans: A
Chapter 18: TEMPERATURE, HEAT, AND THE FIRST LAW OF THERMODYNAMICS
281
56. During the time that latent heat is involved in a change of state:
A. the temperature does not change
B. the substance always expands
C. a chemical reaction takes place
D. molecular activity remains constant
E. kinetic energy changes into potential energy
ans: A
57. The formation of ice from water is accompanied by:
A. absorption of energy as heat
B. temperature increase
C. decrease in volume
D. an evolution of heat
E. temperature decrease
ans: A
58. How many calories are required to change one gram of 0 C ice to 100 C steam? The latent
heat of fusion is 80 cal/g and the latent heat of vaporization is 540 cal/g. The specic heat of
water is 1.00 cal/g K.
A. 100
B. 540
C. 620
D. 720
E. 900
ans: D
59. Ten grams of ice at 20 C is to be changed to steam at 130 C. The specic heat of both
ice and steam is 0.5 cal/g C . The heat of fusion is 80 cal/g and the heat of vaporization is
540 cal/g. The entire process requires:
A. 750 cal
B. 1250 cal
C. 6950 cal
D. 7450 cal
E. 7700 cal
ans: D
60. Steam at 1 atm and 100 C enters a radiator and leaves as water at 1 atm and 80 C. Take the
heat of vaporization to be 540 cal/g. Of the total energy given o as heat, what percent arises
from the cooling of the water?
A. 100
B. 54
C. 26
D. 14
E. 3.6
ans: E
282
61. A certain humidier operates by raising water to the boiling point and then evaporating it.
Every minute 30 g of water at 20 C are added to replace the 30 g that are evaporated. The
heat of fusion of water is 333 kJ/kg, the heat of vaporization is 2256 kJ/kg, and the specic
heat is 4190 J/kg K. How many joules of energy per minute does this humidier require?
A. 3.0 104
B. 8.8 104
C. 7.8 104
D. 1.1 105
E. 2.0 104
ans: B
62. A metal sample of mass M requires a power input P to just remain molten. When the heater
is turned o, the metal solidies in a time T . The specic latent heat of fusion of this metal is:
A. P/M T
B. T /P M
C. P M/T
D. P M T
E. P T /M
ans: E
63. Fifty grams of ice at 0 C is placed in a thermos bottle containing one hundred grams of water
at 6 C. How many grams of ice will melt? The heat of fusion of water is 333 kJ/kg and the
specic heat is 4190 J/kg K.
A. 7.5
B. 2.0
C. 8.3
D. 17
E. 50
ans: A
64. According to the rst law of thermodynamics, applied to a gas, the increase in the internal
energy during any process:
A. equals the heat input minus the work done on the gas
B. equals the heat input plus the work done on the gas
C. equals the work done on the gas minus the heat input
D. is independent of the heat input
E. is independent of the work done on the gas
ans: B
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65. Pressure versus volume graphs for a certain gas undergoing ve dierent cyclic processes are
shown below. During which cycle does the gas do the greatest positive work?
p
p
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V
A
p
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V
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E
ans: D
66. During an adiabatic process an object does 100 J of work and its temperature decreases by 5 K.
During another process it does 25 J of work and its temperature decreases by 5 K. Its heat
capacity for the second process is:
A. 20 J/K
B. 24 J/K
C. 5 J/K
D. 15 J/K
E. 100 J/K
ans: D
67. A system undergoes an adiabatic process in which its internal energy increases by 20 J. Which
of the following statements is true?
A. 20 J of work was done on the system
B. 20 J of work was done by the system
C. the system received 20 J of energy as heat
D. the system lost 20 J of energy as heat
E. none of the above are true
ans: A
68. In an adiabatic process:
A. the energy absorbed as heat equals the work done by the system on its environment
B. the energy absorbed as heat equals the work done by the environment on the system
C. the absorbed as heat equals the change in internal energy
D. the work done by the environment on the system equals the change in internal energy
E. the work done by the system on its environment equals to the change in internal energy
ans: D
284
69. In a certain process a gas ends in its original thermodynamic state. Of the following, which is
possible as the net result of the process?
A. It is adiabatic and the gas does 50 J of work
B. The gas does no work but absorbs 50 J of energy as heat
C. The gas does no work but loses 50 J of energy as heat
D. The gas loses 50 J of energy as heat and does 50 J of work
E. The gas absorbs 50 J of energy as heat and does 50 J of work
ans: E
70. Of
A.
B.
C.
D.
E.
the following which might NOT vanish over one cycle of a cyclic process?
the change in the internal energy of the substance
the change in pressure of the substance
the work done by the substance
the change in the volume of the substance
the change in the temperature of the substance
ans: C
71. Of
A.
B.
C.
D.
E.
the following which might NOT vanish over one cycle of a cyclic process?
the work done by the substance minus the energy absorbed by the substance as heat
the change in the pressure of the substance
the energy absorbed by the substance as heat
the change in the volume of the substance
the change in the temperature of the substance
ans: C
285
74. The rate of heat ow by conduction through a slab does NOT depend upon the:
A. temperature dierence between opposite faces of the slab
B. thermal conductivity of the slab
C. slab thickness
D. cross-sectional area of the slab
E. specic heat of the slab
ans: E
75. The rate of heat ow by conduction through a slab is Pcond . If the slab thickness is doubled,
its cross-sectional area is halved, and the temperature dierence across it is doubled, then the
rate of heat ow becomes:
A. 2Pcond
B. Pcond /2
C. Pcond
D. Pcond /8
E. 8Pcond
ans: B
76. The diagram shows four slabs of dierent materials with equal thickness, placed side by side.
Heat ows from left to right and the steady-state temperatures of the interfaces are given.
Rank the materials according to their thermal conductivities, smallest to largest.
d d d d
35 C
A.
B.
C.
D.
E.
1, 2, 3,
2, 1, 3,
3, 4, 1,
3, 4, 2,
4, 3, 2,
ans: D
30 C
20 C
0 C
15 C
4
4
2
1
1
77. Inside a room at a uniform comfortable temperature, metallic objects generally feel cooler to
the touch than wooden objects do. This is because:
A. a given mass of wood contains more heat than the same mass of metal
B. metal conducts heat better than wood
C. heat tends to ow from metal to wood
D. the equilibrium temperature of metal in the room is lower than that of wood
E. the human body, being organic, resembles wood more closely than it resembles metal
ans: B
286
78. On a very cold day, a child puts his tongue against a fence post. It is much more likely that
his tongue will stick to a steel post than to a wooden post. This is because:
A. steel has a higher specic heat
B. steel is a better radiator of heat
C. steel has a higher specic gravity
D. steel is a better heat conductor
E. steel is a highly magnetic material
ans: D
79. An
A.
B.
C.
D.
E.
iron stove, used for heating a room by radiation, is more e cient if:
its inner surface is highly polished
its inner surface is covered with aluminum paint
its outer surface is covered with aluminum paint
its outer surface is rough and black
its outer surface is highly polished
ans: D
80. To help keep buildings cool in the summer, dark colored window shades have been replaced by
light colored shades. This is because light colored shades:
A. are more pleasing to the eye
B. absorb more sunlight
C. reect more sunlight
D. transmit more sunlight
E. have a lower thermal conductivity
ans: C
81. Which of the following statements pertaining to a vacuum ask (thermos) is NOT correct?
A. Silvering reduces radiation loss
B. Vacuum reduces conduction loss
C. Vacuum reduces convection loss
D. Vacuum reduces radiation loss
E. Glass walls reduce conduction loss
ans: D
82. A thermos bottle works well because:
A. its glass walls are thin
B. silvering reduces convection
C. vacuum reduces heat radiation
D. silver coating is a poor heat conductor
E. none of the above
ans: E
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