# Thermodynamics 4

Mechanical Engineering MCQ Question Papers: DRDO, ISRO, Interview

Subject:  Thermodynamics 4

Part 4: List for questions and answers of Thermodynamics

Q1. What is an ideal gas?
a) Which obeys the law pv = RT
b) Which obeys the law p = vr / T
c) Which obeys the law pv = R / T
d) None of the above

Q2. The perfect example of an ideal gas is
a) Air
b) Hydrogen
c) Water vapour
d) None of the above

Q3. In which condition can real gas obey closely the ideal gas equation?
a) Pressure is very small and temperature is very high
b) Pressure is very high and temperature is very low
c) Both pressure and temperature are very high
d) Both pressure and temperature are very low

Q4. In high pressure condition, the real gases conform more closely with
a) Van der Waals equation
b) Ideal gas equation
c) Both a. And b
d) None of the above

Q5. What is reduced property of a substance?
a) Critical property of a substance minus existing property of the same substance
b) Existing property of a substance minus critical property of the same substance
c) Ratio of critical property to existing property of the same substance
d) Ratio of existing property to critical property of the same substance

Q6. In a mixture of ideal gases of volume V and temperature T, what is the pressure exerted by each individual gas if it occupies the total volume V alone at temperature T called?
a) Individual pressure
b) Divided pressure
c) Partial pressure
d) Total pressure

Q7. The sum of partial volumes of all gases in a mixture is equal to
a) Less than the total volume of the mixture
b) The total volume of the mixture
c) More than the total volume of the mixture
d) Cannot predict

Q8. The engines which are operating on gas power cycle are
a) Cyclic
b) Non-cyclic
c) Either cyclic or non-cyclic
d) None of the above

Q9. Internal combustion engine is the example of
a) Cyclic heat engine
b) Non-cyclic heat engine
c) Both a. And b
d) None of the above

Q10. The cycle which consists of two reversible isotherms and two reversible isochores is called as
a) Rankine cycle
b) Carnot cycle
c) Stirling cycle
d) Ericsson cycle

Q11. Two reversible isothermal processes and two reversible isobaric processes are carried out in
a) Rankine cycle
b) Carnot cycle
c) Stirling cycle
d) Ericsson cycle

Q12. Which thermodynamic cycle, for the same condition, has highest efficiency among theothers?
a) Carnot cycle
b) Stirling cycle
c) Ericsson cycle
d) None. All of the above have same efficiency

Q13. What is the reason of the fact that the internal combustion engine does not complete thermodynamic cycle?
a) Because every time fresh air is taken inside the engine and combustion products are thrown out of the engine
b) Because permanent chemical change is undergone by the working fluid in
combustion chamber
c) Both a. And b
d) None of the above

Q14. The purpose of study of air standard cycle is
a) To simplify the analysis of internal combustion engine
b) To increase the efficiency of internal combustion engine
c) Both a. And b
d) None of the above

Q15. Otto cycle is the air standard cycle of
a) Spark ignition (SI) engine
b) Compression (CI) ignition engine
c) Both SI and CI engines
d) None of the above

Q16. How is the heat added in the Otto cycle?
a) Reversibly at constant pressure
b) Irreversibly at constant pressure
c) Reversibly at constant volume
d) Irreversibly at constant volume

Q17. What is the relation between compression ratio (rk) and the efficiency of the Otto cycle?
a) Efficiency decreases with increase in compression ratio
b) Efficiency increases with increase in compression ratio
c) Efficiency does not affected by change in compression ratio
d) None of the above

Q18. The compression ratio cannot be increased beyond certain limit, because it results to
a) Auto-ignition of fuel
b) Detonation
c) Engine knocking
d) All of the above

Q19. For the same capacity engines, the compression ratio of diesel engine
a) Is lower than the compression ratio of SI engine
b) Is higher than the compression ratio of SI engine
c) Is same as the compression ratio of SI engine
d) Cannot say

Q20. Rate of burning in the compression ignition engine can be controlled by
a) Rate of injection of fuel
b) Rate of air taken into carburettor
c) Both a. And b
d) None of the above

Part 4: List for questions and answers of Thermodynamics