Thermodynamics and Refrigeration Systems Mid - I, September - 2014

1.The state of a substance whose evaporation from its liquid state is completeis known as
  • Steam
  • Vapor
  • Air
  • Perfect gas
Answer: D
2.Which of the following are boiler accessories
  • Safety valve
  • Super heater
  • Economizer
  • both b & c
Answer: D
3.The mass of cooling water, circulating through the cylinder jackets, as well as its inlet and outlet temperatures are measured in order to determine the
  • Heat absorbed in IP produced
  • Heat rejected to the cooling water
  • Heat supplied by fuel
  • Heat carried away by exhaust gases
Answer: B
4.The ratio of work obtained at the crank shaft in a given time to the energy supplied by
the fuel during the same time is called
  • Mechanical efficiency
  • Overall efficiency
  • Brake thermal efficiency
  • Indicated thermal efficiency
Answer: B
5.Which of the following is an intensive property of a thermodynamic system
  • Volume
  • Temperature
  • Mass
  • Energy
Answer: B
6.A cycle consisting of two constant volume and two isothermal processes is known as
  • Carnot cycle
  • Joule cycle
  • Diesel cycle
  • Stirling cycle
Answer: C
7.The thermal efficiency of petrol engine is about
  • 15%
  • 26%
  • 46%
  • 70%
Answer: B
8.A spring loaded safety valve is mainly used for
  • Locomotive and Marine boilers
  • Lancashire and Cornish boilers
  • Cornish and Babcock-Wilcox boilers
  • Marine and Lancashire boilers
Answer: A
9.For steam, the critical temperature is 
  • 273.150C
  • 212.250C
  • 374.150C
  • 423.150C
Answer: C
10.The work done in a free expansion process is
  • Zero
  • Minimum
  • Maximum
  • Positive
Answer: A
11.When a system changes its state from one equilibrium state to another equilibrium state, then the path of successive states through which the system has passed is called _____________________________
Answer: Thermodynamic process
12.The energy transferred across the boundary of a system because of an intensive property difference other
than temperature that exists between the system and surroundings is called ________________
Answer: Work
13.A process in which the gas is heated or expanded in such a way that the product of its pressure and volume
remains constant is called a ____________________
Answer: Hyperbolic process
14.Entropy may be expressed as a function of _____________________________
Answer: Pressure and temperature
15.The performance of a heat engine is measured in terms of ______________________
Answer: Thermal efficiency
16.The ratio of the mass of actual dry steam to the mass of same quantity of wet steam
iscalled________________
Answer: Dryness fraction
17.A device which is attached to the steam chest for preventing explosions due to excessive internal pressure
of steam is called __________________
Answer: Safety valve
18.The test which is adopted to find the indicated power of each cylinder of a high speed IC engine, without
using indicator diagram is ___________________
Answer: Morse test
19.The complete record of heat supplied and heat rejected during a certain time by an IC engine is entered in a
tabulated form is known as ___________________
Answer: Heat Balance sheet
20.Diesel cycle also known as ____________________________
Answer: Constant pressure cycle