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1 | |
In the absence of friction, heat engines are 100 percent efficient. |
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| | A) | True |
| | B) | False |
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2 | |
If the first law of thermodynamics is satisfied, the second law will also be satisfied. |
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| | A) | True |
| | B) | False |
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3 | |
In every thermodynamic process, the heat absorbed by a system must equal the sum of the work done by the system and its change in internal energy. |
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| | A) | True |
| | B) | False |
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4 | |
An isochoric process is graphed as a straight line on a P-V diagram. |
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| | A) | True |
| | B) | False |
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5 | |
In an adiabatic process, the internal energy will increase when work is done on the system, whereas it will decrease when work is done by the system. |
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| | A) | True |
| | B) | False |
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6 | |
During an isothermal expansion, all the absorbed thermal energy is converted to useful work. |
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| | A) | True |
| | B) | False |
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7 | |
All Carnot engines are perfect engines and, therefore, operate at 100 percent efficiency. |
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| | A) | True |
| | B) | False |
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8 | |
The greater the difference between the input and output temperatures of a steam engine, the greater the efficiency of the engine. |
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| | A) | True |
| | B) | False |
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9 | |
A high compression ratio of an internal combustion engine means a higher operating efficiency. |
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| | A) | True |
| | B) | False |
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10 | |
The coefficient of performance for a refrigerator is a measure of cooling efficiency and is expressed as a percentage. |
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| | A) | True |
| | B) | False |
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11 | |
The thermodynamic state of a gas refers to |
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| | A) | its pressure |
| | B) | its volume |
| | C) | its temperature |
| | D) | all of these |
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12 | |
The net work accomplished by an engine undergoing adiabatic compression is equal to |
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| | A) | ΔU |
| | B) | -ΔU |
| | C) | ΔQ |
| | D) | -ΔQ |
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13 | |
An engine that operates with 100 percent efficiency |
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| | A) | is a Carnot engine |
| | B) | violates the first law |
| | C) | has an Otto cycle |
| | D) | violates the second law |
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14 | |
If a heat engine absorbs heat at 600 K and rejects heat at 200 K, its efficiency is |
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| | A) | 33 percent |
| | B) | 50 percent |
| | C) | 67 percent |
| | D) | 80 percent |
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15 | |
In a Carnot cycle, 1600 cal is absorbed at 600 K, and 400 cal is exhausted to a cold reservoir. The temperature of the cold reservoir is |
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| | A) | 150 K |
| | B) | 200 K |
| | C) | 450 K |
| | D) | 800 K |
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16 | |
An adiabatic process is one in which |
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| | A) | the temperature is constant |
| | B) | the pressure is constant |
| | C) | the volume is constant |
| | D) | no heat enters or leaves the system |
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17 | |
If the adiabatic constant is 1.4 and the compression ratio is 6, a gasoline engine has an efficiency of |
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| | A) | 45 percent |
| | B) | 51 percent |
| | C) | 56 percent |
| | D) | 64 percent |
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18 | |
For a Carnot engine to operate with an efficiency of 100 percent, the exhaust temperature must be |
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| | A) | 0°C |
| | B) | 0 K |
| | C) | infinite |
| | D) | equal to the input temperature |
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19 | |
In a mechanical refrigerator, the low-temperature coils of the evaporator are at -23°C, and the compressed gas in the condenser has a temperature of 77°C. The coefficient of performance is |
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| | A) | 20 percent |
| | B) | 70 percent |
| | C) | 0.23 |
| | D) | 2.5 |
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20 | |
In a typical refrigerator, heat is extracted from the interior by the |
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| | A) | compressor |
| | B) | evaporator |
| | C) | condenser |
| | D) | throttling valve |
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21 | |
The efficiency of a heat engine is the ratio of the to the . |
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22 | |
A(n) process is one in which the volume remains constant, whereas in a(n) process the temperature is constant. |
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23 | |
The throttling process is an example of a(n) process. |
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24 | |
The area under the curve on a P-V diagram represents the in a thermodynamic process. |
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25 | |
Three coordinates used to describe the thermodynamic state of a system are , , and . |
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26 | |
The is essentially a restatement of the conservation of
energy. |
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27 | |
A(n) is a heat engine operating in reverse. Its effectiveness is measured by the . |
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28 | |
Four essential elements of a typical refrigerator include the , , ,
and . |
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29 | |
The fact that all natural spontaneous processes are irreversible is a consequence of the . |
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30 | |
A(n) engine has the maximum possible efficiency for an engine that absorbs heat from one reservoir, performs work, and rejects heat to another reservoir at a lower temperature. |
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