# Thermal Engineering 8

Objective Questions and Answer: Thermal Engineering 8

Subject: Thermal Engineering 8

Part 8: Objective questions and answers of Thermal Engineering

Q1. The term N.T.P. stands for

a) Nominal temperature and pressure

b) Natural temperature and pressure

c) Normal temperature and pressure

d) Normal thermodynamic practice

Q2. A heat exchange process in which the product of pressure and volume remains constant is known as

a) Heat exchange process

b) Throttling process

c) Isentropic process

d) Hyperbolic process.

Q3. In an isothermal process, the internal energy of gas molecules

a) Increases

b) Decreases

c) Remains constant

d) May increase/decrease depending on the properties of gas

Q4. Zeroth law of thermodynamics

a) Deals with conversion of mass and energy

b) Deals with reversibility and irreversibility of process

c) States that if two systems are both in equilibrium with a third system, they are in thermal equilibrium with each other

d) Deals with heat engines

Q5. If a certain amount of dry ice is mixed with same amount of water at 80°C, the final temperature of mixture will be

a) 80°C

b) 0°C

c) 40°C

d) 20°C

Q6. The basis for measuring thermodynamic property of temperature is given by

a) Zeroth law of thermodynamics

b) First law of thermodynamics

c) Second law of thermodynamics

d) Third law of thermodynamics

Q7. One watt is equal to

a) 1 Nm/s

b) 1 N/mt

c) 1 Nm/hr

d) 1 knm/hr

Q8. Work done is zero for the following process

a) Constant volume

b) Free expansion

c) Throttling

d) All Of the above

Q9. For which of the following substances, the gas laws can be used with minimum error

a) Dry steam

b) Wet steam

c) Saturated steam

d) Superheated steam

Q10. In a non-flow reversible process for which p = (- 3V+ 15) x 10^5N/m^2,V changes from 1 m to 2 m^3. The work done will be about

a) 100 xloo^5 joules

b) Lxlo^5 joules

c) 10 xlo^5 joules

d) 10 xlo^5 kilo joules

Q11. The value of the product of molecular weight and the gas characteristic constant for all the gases in M.K.S. unit is

a) 29.27 kgfm/mol°K

b) 8314kgfm/mol°K

c) 848kgfm/mol°K

d) 427kgfm/mol°K

Q12. On volume basis, air contains following parts of oxygen

a) 21

b) 23

c) 25

d) 77

Q13. Universal gas constant is defined as equal to product of the molecular weight of the gas and

a) Specific heat at constant pressure

b) Specific heat at constant volume

c) Ratio of two specific heats

d) Gas constant

Q14. The value of the product of molecular weight and the gas characteristic constant for all the gases in S.I. units is

a) 29.27 J/kmol°K

b) 83.14J/kmol°K

c) 848J/kmol°K

d) All J/kmol °K

Q15. For which of the following substances, the internal energy and enthalpy are the functions of temperature only

a) Any gas

b) Saturated steam

c) Water

d) Perfect gas

Q16. In a free expansion process

a) Work done is zero

b) Heat transfer is zero

c) Both (a) and (b) above

d) Work done is zero but heat increases

Q17. If a gas vapour is allowed to expand through a very minute aperture, then such a process is known as

a) Free expansion

b) Hyperbolic expansion

d) Throttling.

Q18. The specific heat of air increases with increase in

a) Temperature

b) Pressure

c) Both pressure and temperature

d) Variation of its constituents

Q19. If a fluid expands suddenly into vacuum through an orifice of large dimension, then such a process is called

a) Free expansion

b) Hyperbolic expansion

d) Parabolic expansion

Q20. Which of the following processes are thermodynamically reversible?

a) Throttling

c) Constant volume and constant pressure

d) Hyperbolic and pv = C

Part 8: Objective questions and answers of Thermal Engineering