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This set of Thermodynamics Multiple Choice Questions & Answers (MCQs) focuses on Thermodynamics Set 5

Q1 | 287 J/kg/?k is the value of
  • Gas constant in MKS units
  • Gas constant in S.I. units
  • Universal gas constant in MKS units
  • Universal gas constant in S.I. units
  • None of the above
Q2 | The velocity potential exists
  • Only for unidirectional flow
  • Only for rotational flow
  • For all types of continuous flow
  • Only for laminar flow
  • Only for irrotational flow
Q3 | The number of degrees of freedom in case of diatomic gases is
  • 2
  • 3
  • 5
  • 6
  • 4
Q4 | Which of the following statement is correct?
  • Both heat and work are path functions
  • Pulsejet
  • Systems never possess heat but work can be
  • While work is a boundary phenomenon heat is not
  • Both heat and work are inexact differentials
Q5 | Identify the correct statement
  • All substances emit radiation the quality and quantity depends on the absolute temperature and properties of the material composing the radiating body
  • Only some substances emit radiation
  • Quality and quantity of radiation depends on the properties of the material only
  • A substance will emit radiation at a particular wavelength only
  • Bodies black in colour are known as black bodies in radiation
Q6 | Which of the following changes during throttling process?
  • Pressure
  • Temperature
  • Internal energy
  • Pressure x Volume
  • All of the above
Q7 | The molecular weights of all the perfect gases occupy the same volume under same conditions of pressure and temperature".
  • Boyle's law
  • Regnault's law
  • Avogadro's hypothesis
  • Balton's law
  • Gay Lussac's law
Q8 | In which case the heat transferred from the air when compressed from 1.05 ata 15?C to 6.3 ata would be minimum?
  • Adiabatic
  • Polytropic pv1.3 = C
  • Polytropic pv1.31 = C
  • Polytropic pv1.35 = C
  • Isothermal
Q9 | The specific heat of water
  • Decreases with rise of temperature
  • First increases, reaches a maximum value and then decreases.
  • Increases with rise of temperature
  • First decreases, reaches a minimum value and then increases
  • Does not change with temperature
Q10 | If during a process the entropy of a isolated system increases, the process is
  • Ideal
  • Reversible
  • Irreversible
  • Polytropic
  • None of the above
Q11 | The number of processes in a Rankine cycle is
  • Four
  • Five
  • Three
  • Six
  • Two
Q12 | Ericsson cycle processes are
  • Two adiabatic, constant volume and constant pressure
  • Two isothermals and two constant pressures
  • Two isothermals and two isentropics
  • Two isothermals and two constant volumes
  • Two isothermals and two isentropics
Q13 | In a Joule cycle, the heat is rejected at
  • Constant pressure
  • Constant enthalpy
  • Constant temperature
  • Constant volume
  • Constant entropy
Q14 | Isentropic flow is
  • Irreversible adiabatic flow
  • Ideal fluid flow
  • Change in entropy is zero
  • Frictionless reversible flow
  • Perfect gas flow
Q15 | The triple point for carbondioxide is at about -56.7 C and about 5 atm, pressure. It means that
  • Mass transfer at triple point is maximum
  • When CO2 is exposed to a below 5 atmosphere pressure only solid and liquid phase exist together
  • Above 56.7 C CO2 exists only as a liquid
  • Below 57.7 C CO2 exists only in liquid form
  • When solid CO2 is exposed to 1 atm pressure it begins to change directly to gas
Q16 | In a reversible cycle, the entropy of the system
  • Depends on the properties of working substance
  • Decreases
  • Does not change
  • Increases
  • First increases and then decreases
Q17 | The first law of thermodynamics, for steady flow
  • Accounts for all energy entering and leaving a control volume
  • Is primarily concerned with heat transfer
  • Is restricted in its application to perfect gases
  • Is an energy balance for the specified mass of fluid
  • Is an expression of the conservation of linear momentum
Q18 | The unit of universal gas constant is
  • dynes/?K
  • erg/?K
  • W/m?K
  • kcal/?K
  • W/?K
Q19 | Which of the following is not a characteristic of liquid air?
  • It will cause rubber to become brittle
  • Pulsejet
  • It will freeze mercury and ammonia
  • It has no surface tension
  • It will separate out lead from solder
Q20 | Which of the following relation does not hold good for a throttling process?
  • dQ = 0
  • dS = 0
  • Pulsejet
  • dH = 0
  • dW = 0
Q21 | According to Amagat's law
  • the sum of the volume friction is unity
  • there would be no volume change if the components are mixed while holding the temperature and pressure constant
  • all diatomic gases occupy double the volume of monoatomic gases for identical masses
  • None of the above
  • Pulsejet
Q22 | In the polytropic process pvn = Constant if n = 1 the process is termed as
  • Adiabatic
  • Constant pressure
  • Constant temperature
  • Constant volume
  • Isothermal
Q23 | Otto cycle consists of the set of processes as
  • Two isentropics and two constant volumes
  • Two isothermal and two constant volume
  • Two isentropics and two constant pressure
  • Two adiabatic and two isothermal
  • Two isothermal and two constant pressure
Q24 | If the two specific heats of a gas are 0.237 and 0.169 respectively, the volume of 3 kg of air at 27?C under a pressure of 3 ata would be
  • 2.5 cu-m
  • 1 cu-m
  • 0.204 cu-m
  • 1.74 cu-m
  • 1.5 cu-m
Q25 | Five people must be lifted in an elevator to a distance of 100 m. The work is found to be 341.2 kJ and the gravitational acceleration is 9.75 m/s2. The average mass per person is
  • Pulsejet
  • 72 kg
  • 70 kg
  • 67.5 kg
  • 65 kg