# Thermal Engineering 5

Objective Questions and Answer: Thermal Engineering 5

Subject: Thermal Engineering 5

Part 5: Objective questions and answers of Thermal Engineering

Q1. Which of the following variables controls the physical properties of a perfect gas?

a) Pressure

b) Temperature

c) Volume

d) All of the above

Q2. Which of the following laws is applicable for the behavior of a perfect gas?

a) Boyle's law

b) Charles'law

c) Gay-Lussac law

d) All of the above

Q3. The unit of temperature in S.I. units is

b) Celsius

c) Fahrenheit

d) Kelvin

Q4. The unit of mass in S.I. units is

a) Kilogram

b) Gram

c) Tonne

d) Quintal

Q5. According to Gay-Lussac law for a perfect gas, the absolute pressure of given mass varies directly as

a) Temperature

b) Absolute

c) Absolute temperature, if volume is kept constant

d) Volume, if temperature is kept constant

Q6. An ideal gas as compared to a real gas at very high pressure occupies

a) More volume

b) Less volume

c) Same volume

d) Unpredictable behaviour

Q7. General gas equation is

a) PV=nrt

b) PV=mrt

c) PV = C

d) PV=kirt

Q8. According to Dalton's law, the total pressure of the mixture of gases is equal to

a) Greater of the partial pressures of all

b) Average of the partial pressures of all

c) Sum of the partial pressures of all

d) Sum of the partial pressures of all divided by average molecular weight

Q9. Which of the following can be regarded as gas so that gas laws could be applicable, within the commonly encountered temperature limits?

a) 02, N2, steam, C02

b) O2, N2, water vapour

c) S02, NH3, C02, moisture

d) 02, N2, H2, air

Q10. The unit of time in S.I. units is

a) Second

b) Minute

c) Hour

d) Day

Q11. The unit of pressure in S.I. units is

a) Kg/cm^2

b) Mm of water column

c) Pascal

d) Dynes per square cm

Q12. A closed system is one in which

a) Mass does not cross boundaries of the system, though energy may do so

b) Mass crosses the boundary but not the energy

c) Neither mass nor energy crosses the boundaries of the system

d) Both energy and mass cross the boundaries of the system

Q13. Temperature of a gas is produced due to

a) Its heating value

b) Kinetic energy of molecules

c) Repulsion of molecules

d) Attraction of molecules

Q14. According to kinetic theory of gases, the absolute zero temperature is attained when

a) Volume of the gas is zero

b) Pressure of the gas is zero

c) Kinetic energy of the molecules is zero

d) Specific heat of gas is zero

Q15. Kinetic theory of gases assumes that the collisions between the molecules are

a) Perfectly elastic

b) Perfectly inelastic

c) Partly elastic

d) Partly inelastic

Q16. The pressure of a gas in terms of its mean kinetic energy per unit volume E is equal to

a) E/3

b) E/2

c) 3E/4

d) 2E/3

Q17. Kinetic energy of the molecules in terms of absolute temperature (T) is proportional to

a) T

b) J

c) J2

d) Vr

Q18. Superheated vapour behaves

a) Exactly as gas

b) As steam

c) As ordinary vapour

d) Approximately as a gas

Q19. Absolute zero pressure will occur

a) At sea level

b) At the center of the earth

c) When molecular momentum of the system becomes zero

d) Under vacuum conditions

Q20. No liquid can exist as liquid at

a) – 273 °K

b) Vacuum

c) Zero pressure

d) Centre of earth

Part 5: Objective questions and answers of Thermal Engineering