Thermodynamics

31. Carnot cycle efficiency is maximum when

1. initial temperature is 0°K
2. final temperature is 0°K
3. difference between initial and final temperature is 0°K
4. final temperature is 0°C
5. initial temperature is minimum possible.

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32. Carnot cycle has maximum efficiency for

1. reversible engine
2. irreversible engine
3. new engine
4. petrol engine
5. diesel engine.

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33. Carnot cycle is

1. a reversible cycle (ft) an irreversible cycle
2. a semi-reversible cycle
3. a quasi static cycle
4. an adiabatic irreversible cycle.
5. None of above

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34. Change in enthalpy in a closed system is equal to heat transferred if the reversible process takes place at constant

1. pressure
2. temperature
3. volume
4. internal energy
5. entropy.

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35. Change in enthalpy of a system is the heat supplied at

1. constant pressure
2. constant temperature
3. constant volume
4. constant entropy
5. N.T.P. condition.

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36. Change in internal energy in a closed system is equal to heat transferred if the reversible process takes place at constant

1. pressure
2. temperature
3. volume
4. internal energy
5. entropy.

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37. Characteristic gas constant of a gas is equal to

1. C/Cv
2. Cv/Cp
3. Cp - Cv
4. Cp + Cv
5. Cp x Cv

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38. Compressed air coming out from a punctured football

1. becomes hotter
2. becomes cooler1
3. remains at the same temperature
4. may become hotter or cooler depend-ing upon the humidity of the surround¬ing air
5. attains atmospheric temperature.

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39. Curve A in Fig. 1.1 compared to curves B and C shows the following type of expansion

1. pV"=C
2. isothermal
3. adiabatic
4. free expansion
5. throttling.

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40. Diesel cycle consists of following four processes

1. two isothermals and two isentropics
2. two isentropics, and two constant volumes.
3. two isentropics, one constant volume and one constant pressure
4. two isentropics and two constant pressures
5. none of the above.

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