4791 + Mcqs in Mechanical Engineering Page 88 McqOptions

4351.	The knocking tendency in spark ignition engines can be decreased by adding dopes like tetra ethyle lead and ethylene dibromide.
A.	Agree
B.	Disagree
Answer» B. Disagree

Discussion

4352.	A petrol engine, during suction stroke draws
A.	air only
B.	petrol only
C.	a mixture of petrol and air
Answer» D.

Discussion

4353.	The function of a distributor in a coil ignition system of I.C. engines is
A.	to distribute spark
B.	to distribute power
C.	to distribute current
D.	to time the spark
Answer» E.

Discussion

4354.	The frictional power (F.P.) is given by
A.	F.P. = B.P. - I.P.
B.	F.P. = I.P. - B.P.
C.	F.P. = B.P./I.P.
D.	F.P. = I.P./B.P.
Answer» C. F.P. = B.P./I.P.

Discussion

4355.	If V1 is the jet velocity and V0 is the vehicle velocity, then the propulsive efficiency of a rocket is given by
A.	<img src="/_files/images/mechanical-engineering/ic-engines-and-nuclear-power-plants/350-194-1.png">
B.	<img src="/_files/images/mechanical-engineering/ic-engines-and-nuclear-power-plants/350-194-2.png">
C.	<img src="/_files/images/mechanical-engineering/ic-engines-and-nuclear-power-plants/350-192-2.png">
D.	<img src="/_files/images/mechanical-engineering/ic-engines-and-nuclear-power-plants/350-192-1.png">
Answer» B. <img src="/_files/images/mechanical-engineering/ic-engines-and-nuclear-power-plants/350-194-2.png">

Discussion

4356.	A diesel engine has compression ratio from
A.	6 to 10
B.	10 to 15
C.	15 to 25
D.	25 to 40
Answer» D. 25 to 40

Discussion

4357.	The unit million electron volts (Mev) is commonly used to measure the nuclear energy.
A.	True
B.	False
Answer» B. False

Discussion

4358.	A moderator, apart from its high neutron slowing power, and low non-productive neutron, should be
A.	stable under nuclear radiation
B.	corrossion resistant
C.	good thermal conductor
D.	all of these
Answer» E.

Discussion

4359.	A two stroke cycle engine gives __________ mechanical efficiency than a four stroke cycle engine.
A.	higher
B.	lower
Answer» B. lower

Discussion

4360.	In a petrol engine, the mixture has the lowest pressure at the
A.	beginning of suction stroke
B.	end of suction stroke
C.	end of compression stroke
D.	none of these
Answer» C. end of compression stroke

Discussion

4361.	The delay period in compression ignition engines depends upon
A.	temperature and pressure in the cylinder at the time of injection
B.	nature of the fuel mixture strength
C.	relative velocity between the fuel injection and air turbulence pressure of residual gases
D.	all of the above
Answer» E.

Discussion

4362.	The air standard efficiency of an I.C. engine depends on
A.	fuel used
B.	speed of engine
C.	compression ratio
D.	none of these
Answer» D. none of these

Discussion

4363.	The knocking tendency in spark ignition engines may be decreased by
A.	controlling the air-fuel mixture
B.	controlling the ignition timing
C.	controlling the exhaust temperature
D.	reducing the compression ratio
Answer» E.

Discussion

4364.	Alpha-methyl-naphthalene (C11 H10) has a cetane number of
A.	0
B.	50
C.	100
D.	120
Answer» B. 50

Discussion

4365.	Which of the following does not relate to a spark ignition engine ?
A.	Ignition coil
B.	Spar kplug
C.	Carburettor
D.	Fuel injector
Answer» E.

Discussion

4366.	Lubrication in I.C. engines dissipates the heat generated from the moving parts due to friction.
A.	True
B.	False
Answer» B. False

Discussion

4367.	In a two stroke engine, the working cycle is completed in two revolutions of the crankshaft.
A.	Correct
B.	Incorrect
Answer» C.

Discussion

4368.	A reactor capable of converting a fertile material into fissile isotopes is called regenerative reactor.
A.	Yes
B.	No
Answer» B. No

Discussion

4369.	Spark plugs in automobiles generally have a gap between
A.	0.3 to 0.7 mm
B.	0.2 to 0.8 mm
C.	0.4 to 0.9 mm
D.	0.6 to 1.8 mm
Answer» E.

Discussion

4370.	The injection of fuel by external source is not required in case of engines working on Otto cycle.
A.	Yes
B.	No
Answer» B. No

Discussion

4371.	The running cost of a petrol engine is __________ than that of a diesel engine.
A.	higher
B.	lower
Answer» B. lower

Discussion

4372.	In a petrol engine, if diesel is used, then the engine will
A.	not run
B.	run more efficiently
C.	run at high speed
D.	explode
Answer» B. run more efficiently

Discussion

4373.	The correct sequence of the decreasing order of brake thermal efficiency of the three given basic types of engines is
A.	four stroke C.I. engine, four stroke S.I. engine, two stroke S.I. engine
B.	four stroke S.I. engine, four stroke C.I. engine, two stroke S.I. engine
C.	four stroke C.I. engine, two stroke S.I. engine, four stroke S.I. engine
D.	two stroke S.I. engine, four stroke S.I. engine, four stroke C.I. engine
Answer» B. four stroke S.I. engine, four stroke C.I. engine, two stroke S.I. engine

Discussion

4374.	The engines in which the combustion of fuel takes place inside the engine cylinder are called internal combustion engines.
A.	True
B.	False
Answer» B. False

Discussion

4375.	The theoretically correct mixture of air and petrol is
A.	10:1
B.	15:1
C.	20:1
D.	25:1
Answer» C. 20:1

Discussion

4376.	The indicated power for multi-cylinder engine will be same as that of a single cylinder engine.
A.	True
B.	False
Answer» C.

Discussion

4377.	In order to prevent knocking in spark ignition engines, the charge away from the spark plug should have
A.	low density
B.	low temperature
C.	long ignition delay
D.	all of these
Answer» E.

Discussion

4378.	The size of a reactor at which the chain reaction can be initiated (i.e. when system becomes critical) with just enough fissionable material (called critical mass of fuel) is known as critical size of reactor.
A.	Correct
B.	Incorrect
Answer» B. Incorrect

Discussion

4379.	The ratio of the heat equivalent to one kW hour to the heat in fuel per B.P. hour is termed as brake thermal efficiency.
A.	Yes
B.	No
Answer» B. No

Discussion

4380.	A fuel will detonate less if it has higher self ignition temperature.
A.	True
B.	False
Answer» B. False

Discussion

4381.	The mechanical efficiency ( m) of the engine is given by
A.	<img src="/_files/images/mechanical-engineering/ic-engines-and-nuclear-power-plants/347-163-1.png">
B.	<img src="/_files/images/mechanical-engineering/ic-engines-and-nuclear-power-plants/347-163-2.png">
C.	<img src="/_files/images/mechanical-engineering/ic-engines-and-nuclear-power-plants/347-163-3.png">
D.	none of these
Answer» B. <img src="/_files/images/mechanical-engineering/ic-engines-and-nuclear-power-plants/347-163-2.png">

Discussion

4382.	The increase in intake temperature of internal combustion engines will __________ efficiency.
A.	have no effect on
B.	increase
C.	decrease
Answer» D.

Discussion

4383.	The indicated mean effective pressure of an engine is obtained from the indicator diagram drawn with the help of an engine indicator.
A.	True
B.	False
Answer» B. False

Discussion

4384.	Solid fuel fabricated into various small shapes, which are assembled to form fuel elements, is in the form of
A.	plates
B.	pallets
C.	pins
D.	all of these
Answer» E.

Discussion

4385.	The reflectivity depends upon
A.	geometry of the reflector
B.	energy of neutrons
C.	properties of the reflector
D.	all of these
Answer» E.

Discussion

4386.	A fuel of cetane number 40 has the same ignition quality as a mixture of
A.	40% cetane and 60% alpha methyl napthalene
B.	40% alpha methyl napthalene and 60% cetane
C.	40% petrol and 60% diesel
D.	40% diesel and 60% petrol
Answer» B. 40% alpha methyl napthalene and 60% cetane

Discussion

4387.	The two reference fuels used for cetane rating are
A.	cetane and iso-octane
B.	cetane and alpha-methyl naphthalene
C.	cetane and normal heptane
D.	cetane and tetra ethyl lead
Answer» C. cetane and normal heptane

Discussion

4388.	In petrol engines, the delay period is of the order of
A.	0.001 second
B.	0.002 second
C.	0.003 second
D.	0.004 second
Answer» C. 0.003 second

Discussion

4389.	Reflector in nuclear power plants __________ neutron leakage.
A.	increases
B.	decreases
C.	have no effect on
Answer» C. have no effect on

Discussion

4390.	Number of working strokes per min. for a two stroke cycle engine are __________ the speed of the engine in r.p.m.
A.	equal to
B.	one-half
C.	twice
D.	four-times
Answer» B. one-half

Discussion

4391.	In a petrol engine, the charge is ignited with the help of a spark plug.
A.	Yes
B.	No
Answer» B. No

Discussion

4392.	The injector nozzle of a compression ignition engine is required to inject fuel at a sufficiently high pressure in order to
A.	inject fuel in a chamber of high pressure at the end of compression stroke
B.	inject fuel at a high velocity to facilitate atomisation
C.	ensure that penetration is not high
D.	all of the above
Answer» E.

Discussion

4393.	During idling, a petrol engine requires __________ mixture.
A.	lean
B.	rich
C.	chemically correct
Answer» C. chemically correct

Discussion

4394.	Stoichiometric ratio is
A.	chemically correct air-fuel ratio by weight
B.	chemically correct air-fuel ratio by volume
C.	actual air-fuel ratio for maximum efficiency
D.	none of the above
Answer» C. actual air-fuel ratio for maximum efficiency

Discussion

4395.	Which of the following fuel has little tendency towards detonation ?
A.	Benzene
B.	Iso-octane
C.	Normal heptane
D.	Alcohol
Answer» C. Normal heptane

Discussion

4396.	In petrol engines, using a fixed octane rating fuel, the increase in compression ratio will not effect the knocking tendency.
A.	Agree
B.	Disagree
Answer» C.

Discussion

4397.	Enriched uranium may contain fissionable contents from
A.	1 to 40%
B.	10 to 50%
C.	1 to 80%
D.	1 to 99%
Answer» E.

Discussion

4398.	If the fuel is rich in fissionable material, the reactor can be made more compact than if the percentage of fissionable atoms is small.
A.	Agree
B.	Disagree
Answer» B. Disagree

Discussion

4399.	In a petrol engine, the fuel supplied to the engine cylinder is mixed with required quantity of air and the mixture is ignited with a
A.	fuel pump
B.	fuel injector
C.	spark plug
D.	none of these
Answer» D. none of these

Discussion

4400.	Supercharging is the process of supplying the intake air to the engine cylinder at a density __________ the density of the surrounding atmosphere.
A.	equal to
B.	less than
C.	greater than
Answer» D.

Discussion

Explore topic-wise MCQs in Engineering.

The knocking tendency in spark ignition engines can be decreased by adding dopes like tetra ethyle lead and ethylene dibromide.

A petrol engine, during suction stroke draws

The function of a distributor in a coil ignition system of I.C. engines is

The frictional power (F.P.) is given by

If V1 is the jet velocity and V0 is the vehicle velocity, then the propulsive efficiency of a rocket is given by

A diesel engine has compression ratio from

The unit million electron volts (Mev) is commonly used to measure the nuclear energy.

A moderator, apart from its high neutron slowing power, and low non-productive neutron, should be

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

In a petrol engine, the mixture has the lowest pressure at the

The delay period in compression ignition engines depends upon

The air standard efficiency of an I.C. engine depends on

The knocking tendency in spark ignition engines may be decreased by

Alpha-methyl-naphthalene (C11 H10) has a cetane number of

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

Lubrication in I.C. engines dissipates the heat generated from the moving parts due to friction.

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

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

Spark plugs in automobiles generally have a gap between

The injection of fuel by external source is not required in case of engines working on Otto cycle.

The running cost of a petrol engine is __________ than that of a diesel engine.

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

The correct sequence of the decreasing order of brake thermal efficiency of the three given basic types of engines is

The engines in which the combustion of fuel takes place inside the engine cylinder are called internal combustion engines.

The theoretically correct mixture of air and petrol is

The indicated power for multi-cylinder engine will be same as that of a single cylinder engine.

In order to prevent knocking in spark ignition engines, the charge away from the spark plug should have

The size of a reactor at which the chain reaction can be initiated (i.e. when system becomes critical) with just enough fissionable material (called critical mass of fuel) is known as critical size of reactor.

The ratio of the heat equivalent to one kW hour to the heat in fuel per B.P. hour is termed as brake thermal efficiency.

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

The mechanical efficiency ( m) of the engine is given by

The increase in intake temperature of internal combustion engines will __________ efficiency.

The indicated mean effective pressure of an engine is obtained from the indicator diagram drawn with the help of an engine indicator.

Solid fuel fabricated into various small shapes, which are assembled to form fuel elements, is in the form of

The reflectivity depends upon

A fuel of cetane number 40 has the same ignition quality as a mixture of

The two reference fuels used for cetane rating are

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

Reflector in nuclear power plants __________ neutron leakage.

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

In a petrol engine, the charge is ignited with the help of a spark plug.

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

During idling, a petrol engine requires __________ mixture.

Stoichiometric ratio is

Which of the following fuel has little tendency towards detonation ?

In petrol engines, using a fixed octane rating fuel, the increase in compression ratio will not effect the knocking tendency.

Enriched uranium may contain fissionable contents from

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

In a petrol engine, the fuel supplied to the engine cylinder is mixed with required quantity of air and the mixture is ignited with a

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