Thermodynamics

41. During throttling process

1. heat exchange does not take place
2. no work is done by expanding steam
3. there is no change of internal energy of steam
4. all of the above
5. entropy decreases.

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42. Energy can neither be created nor destroyed but can be converted from one form to other is inferred from

1. zeroth low of thermodynamic
2. first law of thermodynamics
3. second law to thermodynamics
4. basic law of thermodynamics
5. claussius statement.

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43. Entropy change depends on

1. heat transfer
2. mass transfer
3. change of temperature
4. thermodynamic state
5. change of pressure and volume.

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44. Extensive property of a system is one whose value

1. depends on the mass of the system like volume
2. does not depend on the mass of the system, like temperature, pressure, etc.
3. is not dependent on the path followed but on the state
4. is dependent on the path followed and not on the state
5. is always constant.

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45. First law of thermodynamics

1. enables to determine change in internal energy of the system
2. does not help to predict whether the system will or not undergo a change
3. does not enable to determine change in entropy
4. provides relationship between heat, work and internal energy
5. all of the above.

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46. First law of thermodynamics furnishes the relationship between

1. heat and work
2. heat, work and properties of the system
3. various properties of the system
4. various thermodynamic processes
5. heat and internal energy.

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47. For a thermodynamic process to be reversible, the temperature difference between hot body and working substance should be

1. zero
2. minimum
3. maximum
4. infinity
5. there is no such criterion.

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48. For reversible adiabatic process, change in entropy is

1. maximum
2. minimum
3. zero
4. unpredictable
5. negative.

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49. For same compression ratio and for same heat added

1. Otto cycle is more efficient than Diesel cycle
2. Diesel cycle is more efficient than Otto cycle
3. efficiency depends on other factors
4. both Otto and Diesel cycles are equally efficient
5. none of the above.

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50. For which of the following substances, the gas laws can be used with minimum error

1. dry steam
2. wet steam
3. saturated steam
4. superheated steam
5. steam at atmospheric pressure.

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