# 439 Thermodynamic MCQ For All Mechanical Exams

### Thermodynamics

1)The value of ratio of the steam point temperature to the ice point temperature is?

1. a) 1.466
2. b) 1.266
3. c) 1.166
4. d) 1.366

2)Which of the following is chosen as the standard thermometric substance?

1. a) Gas
2. b) Liquid
3. c) Solid
4. d) All of the mentioned

3)A real gas behaves as an ideal gas when?

1. a) Temperature approaches zero
2. b) Pressure approaches zero
3. c) Both temperature and pressure approaches zero
4. d) None of the

4)In the equation dV=(1/p)dW, (1/p) is known as

1. a) volume factor
2. b) pressure factor
3. c) differential factor
4. d) integration factor

5)For a two-stroke engine, work done in one minute is given by

1. a) PmALN
2. b) PmALN/2
3. c) 2PmALN
4. d) none of the mentioned

6)The power available at crankshaft is always _____ indicated power.

1. a) more
2. b) less
3. c) equal
4. d) none of the mentioned

Ans-B

7)Mechanical efficiency of engine is given by

1. a) IP/BP
2. b) 1/(BP*IP)
3. c) (BP*IP)
4. d) BP/IP

Ans-D

8)Shaft work is given by

1. a) T*ω
2. b) T*dθ
3. c) T*τ
4. d) none of the mentioned

Ans-B

9)The surface tension acts to make the surface area of the liquid

1. a) maximum
2. b) minimum
3. c) zero
4. d) none of the mentioned

Ans-B

10)The transfer of heat between a wall and a fluid system in motion is called

2. b) convection
3. c) conduction
4. d) none of the mentioned

Ans-B

11)For solids and liquids, specific heat

1. a) depends on the process
2. b) is independent of the process
3. c) may or may not depend on the process
4. d) none of the mentioned

Ans-B

12)The value of constant of proportionality, J, has the value

1. a) 1
2. b) 0
3. c) -1
4. d) infinity

Ans-A

13)Which of the following is the first law for a closed system undergoing a cycle?

1. a) ∫dW=∫dQ
2. b) J∫dW=∫dQ
3. c) ∫dW=J∫dQ
4. d) none of the mentioned

Ans-C

14)(m*V*V)/2 gives the

1. a) macroscopic kinetic energy
2. b) microscopic kinetic energy
3. c) macroscopic potential energy
4. d) microscopic potential energy

Ans-B

15)m*g*z) gives the

1. a) macroscopic kinetic energy
2. b) microscopic kinetic energy
3. c) macroscopic potential energy
4. d) microscopic potential energy

Ans-C

16)The total internal energy of the system is given by

1. a) U=N/ɛ
2. b) U=Nɛ
3. c) U=ɛ/N
4. d) none of the mentioned

Ans-B

17)Which of the following is true in regard to the energy of an isolated system?

1. a) dQ≠0
2. b) dW≠0
3. c) E=constant
4. d) all of the mentioned

Ans-C

18)The limitation of the first law is

1. a) does not indicate the possibility of a spontaneous process proceeding in a definite direction
2. b) it assigns a quality to different forms of energy
3. c) indicates the direction of any spontaneous process
4. d) none of the mentioned

Ans-A

19)In a constant volume process, internal energy change is equal to

1. a) heat transferred
2. b) work done
3. c) zero
4. d) none of the mentioned

Ans-B

20)For an ideal gas, enthalpy becomes

1. a) h=u-RT
2. b) h=-u-RT
3. c) h=u+RT
4. d) h=-u+RT

Ans-C

21)Heat transferred at constant pressure _____ the enthalpy of a system.

1. a) decreases
2. b) increases
3. c) first decreases then increases
4. d) first increases then decreases

Ans-B

22)Total enthalpy of a system H is given by

1. a) H=h/m
2. b) H=m/h
3. c) H=mh
4. d) none of the mentioned

Ans-C

23)The enthalpy and internal energy are the function of temperature for

1. a) all gases
2. b) steam
3. c) water
4. d) ideal gas

Ans-D

24)The specific heat of a substance at constant volume is defined as the rate of change of ___ with respect to ___

1. a) specific internal energy, temperature
2. b) work, pressure
3. c) specific internal energy, pressure
4. d) heat, temperature

Ans-A

25)The specific heat of a substance at constant pressure is defined as the rate of change of ___ with respect to ___

1. a) work, pressure
2. b) enthalpy, temperature
3. c) enthalpy, pressure
4. d) heat, temperature

Ans-B