Thermal Science Mid - II, November - 2014

1.In a four stroke cycle SI engine the cam shaft runs
  • At the same speed as crankshaft
  • At half the speed of crankshaft
  • At twice of speed of crankshaft
  • At any speed irrespective of crank shaft speed
Answer: B
2.The following is CI engine
  • Diesel engine
  • Petrol engine
  • Gas engine
  • Heat engine
Answer: A
3.The specific fuel consumption of a diesel engine as compared to that for petrol engine is
  • Lower
  • Higher
  • Same for same output
  • Same for same speed
Answer: A
4.The thermal efficiency of gas turbine cycle with ideal regenerative heat exchanger is
  • Equal to work ratio
  • Is less than work ratio
  • Is more than work ratio
  • Unpredictable
Answer: A
5.The knocking tendency in CI engines increase with
  • decrease of compression ratio
  • increase of compression ratio
  • increase the temperature in inlet air
  • increasing cooling water temperature
Answer: A
6.In SI engine, to develop high voltage for spark plug……. used
  • carburettor
  • compressor
  • Ignition coil
  • ingector
Answer: C
7.The following is CI engine
  • Heat engine
  • Petrol engine
  • Gas engine
  • Diesel engine
Answer: D
8.The thermal efficiency of four sstroke engine, when compared to terro stroke engine
  • more
  • less
  • equal
  • can’t say
Answer: A
9.Thermal efficiency of closed cycle gas turbine plant increases by ___________
  • Reheating
  • inter cooling
  • regenerator
  • All of the above
Answer: D
10.The change of entropy, when heat is absorbed by the gas is
  • Positive
  • negative
  • positive or negative
  • all the above
Answer: A
11.In a four stroke cycle engine, the four operations namely suction, compression, expansion and exhaust are completed in the number of revolutions of crank shaft equal to……….
Answer: two
12.Compression ratio of petrol engines is in the range………
Answer: 7 to 10
13.Fuel Injector is used in………
Answer: CI engines
14.In a 4-cyclinder petrol engine the standard firing order is……..
Answer: 1342
15.The function of carburetor is……………
Answer: to maintain correct air fuel mixture
16.Air and fuel mixture is inducted during suction stroke in …………….. engines
Answer: spark ignition
17.Entropy change of universe can never be ……………
Answer: negative
18.Entropy is a ………….function
Answer: point
19.Area under any curve in T-s diagram represents…………
Answer: heat
20.During throttling process entropy ……………for an ideal gas
Answer: increases