| 1. | An ideal gas with heat capacity ratio of 2 is used in an ideal Otto-cycle which operates between minimum and maximum temperatures of 200 K and 1800 K. What is the compression ratio of the cycle for maximum work output ? | |
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1.5
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2
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3
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4
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Report Question| 2. | In an Otto cycle, air is compressed from 3 litres to 2.4 litres from a starting pressure of 1.5 kg/cm². The net output per cycle is 400 kJ. What is the mean effective pressure (kPa) of the cycle ? | |
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500
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567
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667
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700
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| 3. | The combustion in a compression ignition engine is ________ ? | |
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heterogeneous
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homogeneous
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laminar
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turbulent
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| 4. | Which of the following formula holds TRUE for dryness fraction ? | |
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mv/(mv+ml)
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ml/(mv+ml)
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(mv+ml)/ mv
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(mv+ml)/ ml
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| 5. | Which gas will produce the highest efficiency in an ideal Otto cycle for same compression ratio ? | |
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Air
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Carbon dioxide
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Helium
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Oxygen
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| 6. | In Mollier diagram, the isotherm in the superheated region at low pressures becomes ________ ? | |
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diverge from one another
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horizontal
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parallel
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vertical
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| 7. | If the heat rejected from the system is zero, then which of the following statements will hold TRUE ? | |
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When net work is equal to the heat absorbed, work efficiency is 100%
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Heat is exchanged from one heat reservoir only
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It violates Kelvin-Plank statement
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All options are correct
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| 8. | Clausius’ statement and Kelvin-Planck’s statement are ________ ? | |
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not connected
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two parallel statements of the second law
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violation of one does not violates the other
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false statements
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| 9. | For the same heat added and the same compression ratio, ________ ? | |
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Otto cycle is more efficient than diesel cycle
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Diesel cycle is more efficient than Otto cycle
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Both Diesel and Otto cycle are equally efficient
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Cannot be determined
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| 10. | Which equation defines the enthalpy (h) of a system ? | |
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U + pv/J
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U - pv/J
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U + R/Jpv
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U + Jpv
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