# Thermodynamics 2

Mechanical Engineering MCQ Question Papers: DRDO, ISRO, Interview

Subject:  Thermodynamics 2

Part 2: List for questions and answers of Thermodynamics

Q1. If all the variables of a stream are independent of time it is said to be in
a) Steady flow
b) Unsteady flow
c) Uniform flow
d) Closed flow

Q2. A control volume refers to
a) A fixed region in space
b) A specified mass
c) An isolated system
d) A reversible process only

Q3. Internal energy of a perfect gas depends on
a) Temperature, specific heats and pressure
b) Temperature, specific heats and enthalpy
c) Temperature, specific heats and entropy
d) Temperature only

Q4. In reversible polytropic process
a) True heat transfer occurs
b) The entropy remains constant
c) The enthalpy remains constant
d) The internal energy remains constant

Q5. An isentropic process is always
a) Irreversible and adiabatic
b) Reversible and isothermal
c) Frictionless and irreversible
d) Reversible and adiabatic

Q6. In the polytropic process equation pvn = constant, if n is infinitely large, the process is termed as
a) Constant volume
b) Constant pressure
c) Constant temperature
d) Adiabatic

Q7. Steady flow occurs when
a) Conditions do not change with time at any point
b) Conditions are the same at adjacent points at any instant
c) Conditions change steadily with the time
d) None of these

Q8. A reversible process requires that
a) There be no heat transfer
b) Newton’s law of viscosity be satisfied
c) Temperature of system and surroundings be equal
d) There be no viscous or coulomb friction in the system

Q9. The first law of thermodynamics for steady flow
a) Accounts for all energy entering and leaving a control volume
b) Is an energy balance for a specified mass of fluid
c) Is an expression of the conservation of linear momentum
d) Is primarily concerned with heat transfer

Q10. The characteristic equation of gases pv = mrt holds good for
a) Mono atomic gases
b) Diatomic gas
c) Real gases
d) Ideal gases

Q11. A gas which obeys kinetic theory perfectly is known as
a) Mono atomic gas
b) Diatomic gas
c) Real gas
d) Perfect gas

Q12. Work done in a free expansion process is
a) Zero
b) Minimum
c) Maximum
d) Positive

Q13. Which of the following is not a property of the system ?
a) Temperature
b) Pressure
c) Specific volume
d) Heat

Q14. In the polytropic process equation pvn = constant, if n = 0, the process is termed as
a) Constant volume
b) Constant pressure
c) Constant temperature
d) Adiabatic

Q15. The processes or systems that do not involve heat are called
a) Isothermal processes
b) Equilibrium processes
c) Thermal processes
d) Adiabatic processes

Q16. PMM2 is the machine which violates ___
a) Kelvin-Planck statement
b) Clausius statement
c) Both a. And b
d) None of the above

Q17. A cyclic heat engine operates between a source temperature of 927 deg. c and a sink temperature of 27 deg. C. What will be the maximum efficiency of the heat engine?
a) 100 %
b) 80 %
c) 75 %
d) 70 %

Q18. When a process becomes irreversible due to heat interaction between system and surrounding at the boundary due to finite temperature gradient, then the irreversibility is___
a) Internal irreversibility
b) External irreversibility
c) Mechanical irreversibility
d) Chemical irreversibility

Q19. The irreversibility in the system caused by friction is an example of
a) Internal irreversibility
b) External irreversibility
c) Frictional irreversibility
d) Chemical irreversibility

Q20. Assume that a reversible heat engine is operating between a source at T1 and a sink at T2. If T2 decreases, the efficiency of the heat engine ____
a) Decreases
b) Increases
c) Remains constant
d) None of the above

Part 2: List for questions and answers of Thermodynamics

Q1. Answer: a

Q2. Answer: a

Q3. Answer: d

Q4. Answer: a

Q5. Answer: d

Q6. Answer: a

Q7. Answer: a

Q8. Answer: d

Q9. Answer: a

Q10. Answer: c

Q11. Answer: d

Q12. Answer: a

Q13. Answer: d

Q14. Answer: b

Q15. Answer: d

Q16. Answer: c

Q17. Answer: c

Q18. Answer: b

Q19. Answer: a

Q20. Answer: b