An ideal heat engine working between temperatures T1 and T2 has an efficiency η. The new efficiency if both the source and sink temperatures are doubled will be:
1. $\frac{\eta }{2}$
2. η
3. 2η
4. 3η

Subtopic:  Carnot Engine |
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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 |
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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 |
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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 |
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The efficiency of an ideal heat engine (Carnot heat engine) working between the freezing point and boiling point of water is:
1. $$26.8\%$$
2. $$20\%$$
3. $$6.25\%$$
4. $$12.5\%$$

Subtopic:  Carnot Engine |
77%
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NEET - 2018
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In a Carnot engine, when $$T_2=0^\circ \mathrm{C}$$ and $$T_1=200^\circ \mathrm{C},$$ its efficiency is $$\eta_1$$ and when $$T_1=0^\circ \mathrm{C}$$ and $$T_2=-200^\circ \mathrm{C},$$ its efficiency is $$\eta_2.$$ What is the value of $$\frac{\eta_1}{\eta_2}?$$

 1 0.577 2 0.733 3 0.638 4 cannot be calculated
Subtopic:  Carnot Engine |
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Two Carnot engines A and B are operated in succession. The first one, A receives heat from a source at $$T_1=800$$ K and rejects to sink at $$T_2$$ K. The second engine, B, receives heat rejected by the first engine and rejects to another sink at $$T_3=300$$ K. If the work outputs of the two engines are equal, then the value of $$T_2$$ will be:

 1 100 K 2 300 K 3 550 K 4 700 K
Subtopic:  Carnot Engine |
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An ideal gas heat engine operates in a Carnot cycle between 227ºC and 127ºC. It absorbs 6 × 104 cals of heat at higher temperatures. The amount of heat converted to work will be?
1. 4.8 × 104 cals
2. 2.4 × 104 cals
3. 1.2 × 104 cals
4. 6 × 104 cals

Subtopic:  Carnot Engine |
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AIPMT - 2005
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A Carnot engine whose sink is at $$300~\mathrm{K}$$ has an efficiency of $$40$$%. By how much should the temperature of the source be increased to increase its efficiency by $$50$$% of its original efficiency?

 1 $$275~\mathrm{K}$$ 2 $$325~\mathrm{K}$$ 3 $$250~\mathrm{K}$$ 4 $$380~\mathrm{K}$$
Subtopic:  Carnot Engine |
64%
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AIPMT - 2006
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When the sink temperature is kept at 400 K, the efficiency of a Carnot engine is 50%. While keeping the source temperature constant, by how much should we reduce the sink temperature to increase the efficiency to 60%?

 1 80 K 2 70 K 3 320 K 4 240 K
Subtopic:  Carnot Engine |
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