The efficiency of an ideal heat engine is less than \(100\%\) because of:

1.  the presence of friction.
2.  the leakage of heat energy.
3.  unavailability of the sink at zero kelvin.
4.  all of these.

Subtopic:  Carnot Engine |
 85%
Level 1: 80%+
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A heat engine operates between the temperatures of 300 K and 500 K. If it extracts 1200 J of heat energy from the source, then the maximum amount of work that can be done by the engine is:

1. 720 J

2. 520 J

3. 480 J

4. 200 J

Subtopic:  Carnot Engine |
 82%
Level 1: 80%+
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If 3 moles of a monoatomic gas do 150 J of work when it expands isobarically, then a change in its internal energy will be:

1. 100 J 2. 225 J
3. 400 J 4. 450 J
Subtopic:  Molar Specific Heat |
 77%
Level 2: 60%+
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In the case of free expansion, when a sample of gas expands suddenly, the change in internal energy of the gas will be:

1. Positive

2. Negative

3. Zero

4. May be positive or negative

Subtopic:  First Law of Thermodynamics |
 62%
Level 2: 60%+
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The work done for the given process \(AB\) is:

   
1. \(6P_0V_0\)
2. \(5P_0V_0\)
3. \(3P_0V_0\)
4. \(2P_0V_0\)

Subtopic:  Work Done by a Gas |
 55%
Level 3: 35%-60%
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The efficiency of a Carnot heat engine working between the temperatures \(27^{\circ}\mathrm{C}\) and \(227^{\circ}\mathrm{C}\) is:
1. 0.1
2. 0.6
3. 0.2
4. 0.4

Subtopic:  Carnot Engine |
 81%
Level 1: 80%+
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Work done during the given cycle is:
                               
1. 4P0V0

2. 2P0V0

3. 12P0V0

4. P0V0

Subtopic:  Work Done by a Gas |
 81%
Level 1: 80%+
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The cyclic process of \(2\) moles of diatomic gas is shown in the figure. Which of the following statements is correct?

 

1.  The process \(BC\) is an isothermal compression.
2.  The work done in the process \(CA\) is \(4 R T_0\)
3.  The work done in the process \(AB\) is zero.
4.  All of these

Subtopic:  Cyclic Process |
Level 3: 35%-60%
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An ideal gas is enclosed in an insulated cylinder. The piston is frictionless and attached to an ideal spring. When the gas is heated, then:
           

1. the work is done against the spring only.
2. the work is done against the atmospheric pressure only.
3. the internal energy of gas increases.
4. the work is equal to the heat supplied.

Subtopic:  First Law of Thermodynamics |
 61%
Level 2: 60%+
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If a gas undergoes the change in its thermodynamic state from A to B via two different paths, as shown in the given pressure (P) versus volume (V) graph, then:

1. the temperature of the gas decreases in path 1 from A to B.
2. the heat absorbed by the gas in path 1 is greater than in path 2.
3. the heat absorbed by the gas in path 2 is greater than in path 1.
4. the change in internal energy in path 1 is greater than in path 2.

Subtopic:  First Law of Thermodynamics |
 78%
Level 2: 60%+
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