Q.1

A fuel will detonate less if it has higher self ignition temperature.

  • True
  • False
Q.2

Enriched uranium is required as a fuel in a nuclear reactor, if light water is used as moderator and coolant, because light water has

  • high neutron absorption cross-section
  • low moderating efficiency
  • high neutron scatter cross-section
  • low neutron absorption cross-section
Q.3

The fuel valve in a four stroke cycle diesel engine

  • opens at 15° after top dead centre and closes at 20° before bottom dead centre
  • opens at 15° before top dead centre and closes at 20° after top dead centre
  • opens at top dead centre and closes at bottom dead centre
  • may open and close anywhere
Q.4

The spark ignition engines are governed by

  • hit and miss governing
  • qualitative governing
  • quantitative governing
  • combination of (b) and (c)
Q.5

The two reference fuels used for cetane rating are

  • cetane and iso-octane
  • cetane and alpha-methyl naphthalene
  • cetane and normal heptane
  • cetane and tetra ethyl lead
Q.6

In petrol engines, the delay period is of the order of

  • 0.001 second
  • 0.002 second
  • 0.003 second
  • 0.004 second
Q.7

In order to mix air and petrol in the required proportion and to supply it to the engine during suction stroke, then __________ is employed.

  • fuel pump
  • injector
  • carburettor
  • none of these
Q.8

Number of working strokes per min. for a two stroke cycle engine are __________ the speed of the engine in r.p.m.

  • equal to
  • one-half
  • twice
  • four-times
Q.9

In a four stroke engine, the working cycle is completed in

  • one revolution of the crankshaft
  • two revolutions of the crankshaft
  • three revolutions of the crankshaft
  • four revolutions of the crankshaft
Q.10

The reflectivity depends upon

  • geometry of the reflector
  • energy of neutrons
  • properties of the reflector
  • all of these
Q.11

The sparking in a petrol engine increases pressure and temperature of the products of combustion, but the volume remains constant.

  • Yes
  • No
Q.12

A higher compression ratio causes

  • pre-ignition
  • increase in detonation
  • an acceleration in the rate of combustion
  • any one of these
Q.13

In a two stroke engine, the working cycle is completed in two revolutions of the crankshaft.

  • Correct
  • Incorrect
Q.14

A fuel of an octane number rating ofmatches in knocking intensity as a mixture of

  • 75% iso-octane and 25% normal heptane
  • 75% normal heptane and 25% iso-octane
  • 75% petrol and 25% diesel
  • 75% diesel and 25% petrol
Q.15

In a petrol engine, if diesel is used, then the engine will

  • not run
  • run more efficiently
  • run at high speed
  • explode
Q.16

Stoichiometric ratio is

  • chemically correct air-fuel ratio by weight
  • chemically correct air-fuel ratio by volume
  • actual air-fuel ratio for maximum efficiency
  • none of the above
Q.17

The thermal efficiency of a petrol engine is __________ as compared to diesel engine.

  • same
  • less
  • more
Q.18

Supercharging is the process of supplying the intake air to the engine cylinder at a density __________ the density of the surrounding atmosphere.

  • equal to
  • less than
  • greater than
Q.19

The probability of knocking in diesel engines is increased by

  • high self ignition temperature
  • low volatility
  • higher viscosity
  • all of these
Q.20

The combustion in compression ignition engines is

  • homogeneous
  • hetrogeneous
  • both (a) and (b)
  • none of these
Q.21

As compared to air standard cycle, in actual working, the effect of variation in specific heats is to

  • increase maximum pressure and maximum temperature
  • reduce maximum pressure and maximum temperature
  • increase maximum pressure and decrease maximum temperature
  • decrease maximum pressure and increase maximum temperature
Q.22

In petrol engines, advancing of the spark timing will __________ the knocking tendency.

  • not effect
  • decrease
  • increase
Q.23

If petrol is used in a diesel engine, then

  • low power will be produced
  • efficiency will be low
  • higher knocking will occur
  • black smoke will be produced
Q.24

The reflectivity of a reflector is defined as the fraction of neutrons entering the reflector which are returned to the core.

  • Agree
  • Disagree
Q.25

The injector nozzle of a compression ignition engine is required to inject fuel at a sufficiently high pressure in order to

  • inject fuel in a chamber of high pressure at the end of compression stroke
  • inject fuel at a high velocity to facilitate atomisation
  • ensure that penetration is not high
  • all of the above
Q.26

If the fuel is rich in fissionable material, the reactor can be made more compact than if the percentage of fissionable atoms is small.

  • Agree
  • Disagree
Q.27

A gas engine has a swept volume ofcm3 and clearance volume ofcm3. Its volumetric efficiency is 0.and mechanical efficiency is 0.The volume of the mixture taken in per stroke is

  • 248 cm3
  • 252 cm3
  • 264 cm3
  • 286 cm3
Q.28

Which of the following statement is correct ?

  • Compression ratio for petrol engines varies from 6 to 10.
  • Higher compression ratio in diesel engines results in higher pressures.
  • Petrol engines work on Otto cycle.
  • all of the above
Q.29

A reactor capable of converting a fertile material into fissile isotopes is called regenerative reactor.

  • Yes
  • No
Q.30

A two stroke cycle engine gives __________ the number of power strokes as compared to the four stroke cycle engine, at the same engine speed.

  • half
  • same
  • double
  • four times
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