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Mechanical Engineering :: IC Engine and Nuclear Power Plants

  1. The brake power of a diesel engine, keeping other parameters constant, can be increased by

  2. A.
    decreasing the density of intake air
    B.
    increasing the temperature of intake air
    C.
    increasing the pressure of intake air
    D.
    decreasing the pressure of intake air

  3. In diesel engines, the fuel is injected in the form of very fine spray, into the engine cylinder, which gets ignited due to high temperature of the compressed air.

  4. A.
    Agree
    B.
    Disagree

  5. Pre-ignition is caused by the spontantaneous combustion of the mixture before the end of the compression stroke, and is due to

  6. A.
    cylinder walls being too hot
    B.
    overheated spark plug points
    C.
    red hot carbon deposits on cylinder walls
    D.
    any one of these

  7. The expansion of fuel in a four stroke cycle diesel engine

  8. A.
    starts at 15° before top dead centre and ends at 30° after top dead centre
    B.
    starts at top dead centre and ends at 30° after top dead centre
    C.
    starts at 15° after top dead centre and ends at 30° before bottom dead centre
    D.
    may start and end anywhere

  9. The object of supercharging the engine is

  10. A.
    to reduce mass ofthe engine per brake power
    B.
    to reduce space occupied by the engine
    C.
    to increase the power output of an engine when greater power is required
    D.
    all ofthe above

  11. In open combustion chamber in diesel engines, the shape and layout of the piston crown, the inlet port and the valve produce the turbulent effect of fuel mixture.

  12. A.
    True
    B.
    False

  13. In a four stroke cycle petrol engine, the charge is ignited at

  14. A.
    30° before top dead centre
    B.
    30° after top dead centre
    C.
    30° before bottom dead centre
    D.
    30° after bottom dead centre

  15. A moderator, in nuclear power plants, is a medium introduced into the fuel mass in order to

  16. A.
    slow down the speed of fast moving neutrons
    B.
    control the reaction
    C.
    reduce the temperature
    D.
    extract heat from nuclear reaction

  17. Where reactor operation is designed with fast neutrons such as in reactors using highly enriched fuel, the moderator used is

  18. A.
    heavy water
    B.
    graphite
    C.
    carbon dioxide
    D.
    no moderator is needed

  19. In a diesel engine, the duration between the time of injection and ignition, is known as

  20. A.
    pre-ignition period
    B.
    delay period
    C.
    period of ignition
    D.
    burning period