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This set of Engineering Thermodynamics Multiple Choice Questions & Answers (MCQs) focuses on Engineering Thermodynamics Set 6
Q1 | During a throttling process
- a) exchange of heat doesnot take place
- b) expandingsteam does nowork
- c) internal energy of steamdoes not change
- d) all of the above
Q2 | Under which of the following conditionsall gases behave ideally?
- a) high pressure conditions
- b) law pressure conditions
- c) vaccum conditions
- d) all of the aboveconditions
Q3 | ……….. Is the unit of entropy
- a) j/kg
- b) j/kg k
- c) j/k
- d) j/kgs
Q4 | Internal energy & enthalpy of an ideal gasare functions of
- a) pressure only
- b) temperature only
- c) specific volume only
- d) temperature & pressure
Q5 | When two gases suddenly mix up with each other then resultant entropy of thesystem will
- a) remain unaltered
- b) decrease
- c) increase
- d) becomes zero
Q6 | On which of the following factors does air standard efficiency of a diesel cycledepend?
- a) adiabatic compression ratio
- b) ratio of specific heats
- c) cut-off ratio
- d) all of the above
Q7 | Regarding enthalpy which of the following statements is incorrect?
- a) it is the function of specific heat at constantvolume
- b) it is the extensive property of the system
- c) it is the sum of internal energy & the pressurevolume product
- d) it is the same as heat transfer during constantpressure process
Q8 | Which of the following processes isreversible process?
- a) throttling
- b) adiabatic
- c) isothermal
- d) none of the above
Q9 | Which of the following processes arereversible processes?
- a) isothermal & adiabatic
- b) constant volume &constant pressure
- c) hyperbolic & pv?= constant
- d) none of the above
Q10 | For ……. The internal energy & enthalpy are the functions of temperature only
- a) perfect gas
- b) water in pipes surrounded by steam
- c) saturated steam
- d) superheated steam
Q11 | The index of compression n tends to reach ?(ratio of specific heats)
- a) when process is isothermal
- b) when process is isentropic
- c) when process is isentropic & specific heat does not change with temperature
- d) when flow is uniform & steady
Q12 | In the reversible polytropic process the value of exponent n varies between
- a) 0.2 to 1
- b) 1.0 to 1.2
- c) 1.2 to 1.4
- d) 1.4 to 2.0
Q13 | An ideal gas as compared to a real gas atvery high pressure occupies
- a) same volume
- b) less volume
- c) more volume
- d) all of the above
Q14 | For any irreversible process the netentropy change is
- a) unity
- b) infinite
- c) positive
- d) negative
Q15 | Adiabatic & isothermal processes areidentical at
- a) absolute zerotemperature
- b) below 0??c temperature
- c) saturation temperature
- d) critical temperature
Q16 | In polytropic process pv?=C the value ofexponent n=±? is indicative of
- a) isobaric process
- b) isentropic process
- c) isochoric process
- d) throttling process
Q17 | Entropy in statistical thermodynamics isdefined as
- a) a universal property
- b) reversible heat transfer
- c) degree of randomness
- d)measure of reversibilityof a system
Q18 | A mixture of gases expands from 0.03 m³ to 0.06 m³ at a constant pressure of 1 Mpa & absorbs 84 kJ of heat during the process. The change in internal energy ofthe mixture is
- a) 30 kj
- b) 54 kj
- c) 84 kj
- d) 114 kj
Q19 | Increase in entropy of a systemrepresents
- a) increase in availability ofenergy
- b) increase in temperature
- c) decrease in pressure
- d) degradation of energy
Q20 | Which one of the following pairs best expresses a relationship similar to that expressed in the pair 'pressure-volume' for a thermodynamic system undergoinga process?
- a) enthalpy-entropy
- b) pressure-enthalpy
- c) pressure-temperature
- d) temperature-entropy
Q21 | Variations of pressure & volume atconstant temperature are correlated through
- a) charle\s law
- b) boyle\s law
- c) gas law
- d) gay lussac\s law
Q22 | The relationship between pressure & volume is expressed as pv?=const. Selectwrong statement
- a) expansion with n=0 is a constant pressure process
- b) expansion with n=? is an adiabatic process
- c) expansion with n=? is not possible
- d) expansion at constant temperature has n=1
Q23 | A gas expands from initial condition of (p1, v1, T1) to final condition (p2, v1, T2), then according to Charle's law:
- a) p1t1=p2t2
- b) p1p2 = t1t2
- c) p1+ t2 = p2 + t1
- d) p1t2 = p2t1
Q24 | Air expands from initial condition of p1, v1 to final condition of 1/2 p1, 2v1.Choose the correct statement
- a) no work is performed during expansion
- b) expansion is isothermal
- c) expansion is polytropic with n= 1.2
- d) expansion is adiabatic
Q25 | Air with initial condition of p1, v1 expands to final condition of p1/2, 3v1.The process is
- a) hyperbolic
- b) adiabatic
- c) polytropic with n > 1
- d) polytropic with n < 1