Thermodynamics Mid - II, November - 2014

1.Which of the following variables controls the physical properties of a perfect gas
  • pressure
  • temperature
  • volume
  • all of the above
Answer: D
2.Gas laws are applicable to _________
  • gases as well as vapours
  • gases alone and not to vapours
  • gases and steam
  • none of the above
Answer: B
3.During a refrigeration cycle heat is rejected by the refrigerant in___________
  • compressor
  • condenser
  • expansion valve
  • evaporator
Answer: B
4.Specific heat of air at constant volume is equal to ___________
  • 0.24
  • 0.21
  • 0.71
  • 1.4
Answer: C
5.In a reversible process, the change in entropy is _____________________
  • zero
  • minimum
  • maximum
  • unity
Answer: A
6.For same compression ratio and for same heat added otto cycle is ___________efficient than diesel cycle
  • less
  • more
  • equally
  • none
Answer: B
7.For same compression ratio the efficiency of dual combustion cycle is ______ Otto cycle
  • less than
  • more than
  • equal to
  • none
Answer: A
8.Otto cycle consists of following four processes______
  • two isothermal and two isentropic
  • two isentropic and two constant volume
  • two isentropic, one constant volume and one constant pressure
  • two isentropic and two constant pressure
Answer: B
9.The efficiency of Diesel cycle with decrease in cut off __________
  • first increases and then decreases
  • decreases
  • remains unaffected
  • increases
Answer: D
10.Boyle's law states that when temperature is constant, the volume of a given mass of a perfect gas
  • varies directly as the absolute pressure
  • varies inversely as the absolute pressure
  • varies as square of the absolute pressure
  • does not vary with the absolute pressure
Answer: B
11.ankine cycle consists of _______ number of processes.
Answer: isentropic
12.Diesel cycle consists of constantpressure process and two __________processes.
Answer: processes
13.Diesel cycle consists of _______ number of isentropic processes.
Answer: two
14.The equation of the state per kg of a perfect gas is given by
Answer: pv=RT.
15.The value of universal constant is KJ/KgK
Answer: 8.314 KJ/KgK.
16.During humidification process Relative humidity _______________.
Answer: Increases.
17.What is the function of boiler in Rankine cycle __________________.
Answer: Converts water into steam
18.Relative C.O.P. is equal to __________
Answer: Actual C.O.P./Theoretical C.O.P.
19.The value of n=1 in the polytrophic process indicates it to be _____________process
Answer: Isothermal
20.The efficiency of Diesel cycle with decrease in cut-off _______________
Answer: Increases