# Engineering thermodynamics MCQ

Below Engineering thermodynamics quiz are Multiple Choice Questions (MCQs) type Quiz. These Engineering thermodynamics MCQ Questions helps you to refresh your Engineering thermodynamics, you can see the correct option by clicking on it. .
• ### 1. The          obtainable from a certain heat input in a cyclic heat engine is called

• minimum work output, available energy
• maximum work output, available energy
• minimum work input, unavailable energy
• none of the mentioned
• ### 2. Efficiency of a heat engine is defined as

• total heat output / net work input
• total heat input / net work output
• net work output / total heat input
• net work input / total heat output
• ### 3. Which of the following remains constant during an adiabatic expansion

• a) entropy
• b) temperature
• c) internal energy
• d) none of the above
• ### 4. Air expands from initial condition of p1, v1 to final condition of 1/2 p1, 2v1.Choose the correct statement

• a) no work is performed during expansion
• b) expansion is isothermal
• c) expansion is polytropic with n= 1.2
• ### 5. The universal gas constant will be equal to difference between specific heats at constant pressure & constant volume for

• 1 kg mass of gas
• 1 molecule of gas
• 1 kg molecule of gas
• any mass of gas
• ### 6. A power cycle using steam as working fluid consist ofi) constant pressure heat addition ii)adiabatic expansioniii) constant pressure heat rejection & iv) adiabatic compression. The cycle is

• simple rankine cycle
• modified rankine cycle
• carnot cycle
• regenerative rankine cycle

• a) 0.79
• b) 0.815
• c) 0.84
• d) 0.86
• ### 8. The temperature of feed water can be increased in following two ways in a regenerative Rankine cyclei) by passing feed water around turbine casing in direction opposite to flow of steamii) by bleeding certain portion of steam at the end of h.p expansion & mixing with condensate to make feed water at the temperature of boiler

• a) i) is preferred over ii) for higher efficiency
• b) ii) is preferred over i) for reduced moisture content of steam in l.p side
• c) only i) is implemented in actual practice
• d) by preferring ii) overi) significant gain in efficiency results
• ### 9. A regenerative Rankine cycle may approach efficiency of a Carnot cycle between sametemperature by

• a) reducing heat to condenser
• b) reducing volume of steam passed into condenser
• c) increasing turbine work
• d) adding heat a highest temp.
• ### 10. Which of the following contributes to the improvement of efficiency of Rankine cycle in a Thermal Power Plant?

• reheating of steam at intermediate stage
• regeneration use of steam for heating boiler feed water
• use of high pressures
• all of the mentioned