Q.1

Which one of the following engines will have heavier flywheel than the remaining ones?

  • 30 kW four-stroke petrol engine running at 1500 r.p.m.
  • 30 kW two-stroke petrol engine running at 1500 r.p.m.
  • 30 kW two-stroke diesel engine running at 750 r.p.m.
  • 30 kW four-stroke diesel engine running at 750 r.p.m.
Q.2

Which of the following statement is correct regarding the features of a Breeder reactor?

  • It produces more fuel than it consumes.
  • It requires highly enriched fuel.
  • It requires liquid sodium metal as moderator.
  • all of the above
Q.3

The firing order in an I.C. engine depends upon

  • arrangement of the cylinders
  • design of crankshaft
  • number of cylinders
  • all of these
Q.4

The loud pulsating noise heard within the cylinder of an internal combustion engine is known as

  • detonation
  • turbulence
  • pre-ignition
  • supercharging
Q.5

The air standard efficiency ofan I.C. engine is given by (where r = Compression ratio, and γ = Ratio of specific heats)

  • 1 - rγ - 1
    349-177-1.png
  • 1 + rγ - 1
    349-177-1.png
  • none of these
Q.6

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.

  • True
  • False
Q.7

U233 is produced

  • artificially
  • as basic raw material
  • when thorium is irradiated by neutrons
  • by fission of U238
Q.8

Ordinary water is sometimes used as moderator when enriched uranium is used as a fuel in nuclear power plants.

  • Yes
  • No
Q.9

The detonating tendency in petrol engines increases with increase of compression ratio.

  • True
  • False
Q.10

High speed compression engines operate on

  • Otto cycle
  • Diesel cycle
  • Dual-combustion cycle
  • all of these
Q.11

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

  • 30° before top dead centre
  • 30° after top dead centre
  • 30° before bottom dead centre
  • 30° after bottom dead centre
Q.12

The pressure at the end of compression, in diesel engines, is approximately

  • 10 bar
  • 20 bar
  • 25 bar
  • 35 bar
Q.13

Morse test can be conducted for

  • petrol engines
  • diesel engines
  • multi-cylinder engines
  • all of these
Q.14

The ratio of the volume of charge admitted at N.T.P. to the swept volume of the piston is called

  • mechanical efficiency
  • overall efficiency
  • volumetric efficiency
  • relative efficiency
Q.15

A diesel engine has

  • one valve
  • two valves
  • three valves
  • four valves
Q.16

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

  • decreasing the density of intake air
  • increasing the temperature of intake air
  • increasing the pressure of intake air
  • decreasing the pressure of intake air
Q.17

A two stroke cycle engine gives __________ mechanical efficiency than a four stroke cycle engine.

  • higher
  • lower
Q.18

The compensating jet in a carburettor supplies almost constant amount of petrol at all speeds because the

  • jet area is automatically varied depending on the suction
  • the flow from the main jet is diverted to the compensating jet with increase in speed
  • the diameter of the jet is constant and the discharge coefficient is invariant
  • flow is produced due to the static head in the float chamber
Q.19

Each fission of U235 produces on the average __________ fast neutrons as a product of reaction.

  • 2.46
  • 24.6
  • 246
  • 2460
Q.20

In a four stroke cycle petrol engine, the inlet valve

  • opens at top dead centre and closes at bottom dead centre
  • opens at 20° before top dead centre and closes at 40° after bottom dead centre
  • opens at 20° after top dead centre and closes at 20° before bottom dead centre id) may open or close anywhere
Q.21

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

  • slow down the speed of fast moving neutrons
  • control the reaction
  • reduce the temperature
  • extract heat from nuclear reaction
Q.22

The detonation is also called knocking or pinking.

  • Yes
  • No
Q.23

The basic requirement of a good combustion chamber is

  • minimum turbulence
  • low compression ratio
  • high thermal efficiency and power output
  • low volumetric efficiency
Q.24

The exhaust valve in a four stroke cycle petrol engine

  • opens at 50° before bottom dead centre and closes at 15° after top dead centre
  • opens at bottom dead centre and closes at top dead centre
  • opens at 50° after bottom dead centre and closes at 15° before top dead centre
  • may open and close anywhere
Q.25

The self ignition temperature of petrol is __________ as compared to diesel oil.

  • same
  • lower
  • higher
Q.26

The expansion of fuel in a four stroke cycle diesel engine

  • starts at 15° before top dead centre and ends at 30° after top dead centre
  • starts at top dead centre and ends at 30° after top dead centre
  • starts at 15° after top dead centre and ends at 30° before bottom dead centre
  • may start and end anywhere
Q.27

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.

  • Agree
  • Disagree
Q.28

The delay period in compression ignition engines depends upon

  • temperature and pressure in the cylinder at the time of injection
  • nature of the fuel mixture strength
  • relative velocity between the fuel injection and air turbulence pressure of residual gases
  • all of the above
Q.29

Which of the following does not relate to a compression ignition engine?

  • Fuel pump
  • Fuel injector
  • Governor
  • Carburettor
Q.30

A turbo-jet does not require a turbine to drive the compressor.

  • True
  • False
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