I.c. Engines MCQs

Option A: peroxides, aldehydes and ketones

Option B: peroxides, aldehydes, oxides and sul-phides

Option C: aldehydes, oxides and ketones

Option D: ketones and sulphur compounds

Correct Answer: peroxides, aldehydes and ketones ✔

Option A: inject fuel in cylinder

Option B: supply fuel when carburettor fails

Option C: pump fuel so that it reaches carburettor (to improve thermal efficiency)

Option D: does not exist

Correct Answer: pump fuel so that it reaches carburettor (to improve thermal efficiency) ✔

Option A: higher

Option B: lower

Option C: same

Option D: depends on size of engine

Correct Answer: lower ✔

Option A: 0.1 to 0.2 mm

Option B: 0.2 to 0.4 mm

Option C: 0.45 to 0.6 mm

Option D: 0.6 to 0.8 mm

Correct Answer: 0.45 to 0.6 mm ✔

Option A: 0.001 sec

Option B: 0.002 see

Option C: 0.01 sec

Option D: 0.05 sec

Correct Answer: 0.002 see ✔

Option A: minimum temperature to which oil is heated in order to give off inflammable vapours in sufficient quantity to ignite momentarily when brought in contact with a flame

Option B: temperature at which it solidifies or congeals

Option C: that at which it catches fire without external aid

Option D: indicated by 90% distillation temperature, i.e., when 90% of sample oil has distilled off

Correct Answer: that at which it catches fire without external aid ✔

Option A: 30 – 65°C

Option B: 65 – 220°C

Option C: 220-350°C

Option D: 350-450°C

Correct Answer: 65 – 220°C ✔

Option A: 150°C

Option B: 240°C

Option C: 370°C

Option D: 450°C

Correct Answer: more than 500°C. ✔

Option A: iso-octane

Option B: mixture of normal heptane and iso-oc-tane

Option C: alpha methyl napthalene

Option D: mixture of methane and ethane

Correct Answer: mixture of normal heptane and iso-oc-tane ✔

Option A: to increase the octane rating of the fuel

Option B: to increase the cetane rating of the fuel

Option C: as a defrosting agent

Option D: as a superior type of fluid compared to others

Correct Answer: to increase the octane rating of the fuel ✔

Option A: accelerates auto-ignition

Option B: helps to resist auto-ignition

Option C: does not affect auto-ignition

Option D: has no relation with auto-ighition

Correct Answer: helps to resist auto-ignition ✔

Option A: lean mixture has high reaction time

Option B: rich mixture has high reaction time

Option C: chemically correct mixture has mini-mum reaction time

Option D: all of the above

Correct Answer: all of the above ✔

Option A: the time taken by fuel after injection (before top dead center) to reach upto auto-ignition temperature

Option B: time before actual fuel injection and the pump plunger starts to pump fuel

Option C: time corresponding to actual injection and top dead center

Option D: time corresopnding to actual ingition and top dead center

Correct Answer: the time taken by fuel after injection (before top dead center) to reach upto auto-ignition temperature ✔

Option A: heavy turbulence

Option B: improved scavenging

Option C: heavy supercharging

Option D: detonation

Correct Answer: detonation ✔

Option A: cetane

Option B: mixture of cetane and alphamethyl napthalene

Option C: ethylene dibromide

Option D: mixture of aldehydes and ketones

Correct Answer: cetane ✔

Option A: higher

Option B: lower

Option C: same

Option D: depends on quality of fuel

Correct Answer: lower ✔

Option A: has zero cetane number

Option B: has 100 cetane number

Option C: helps detonation

Option D: is a straight chain paraffin

Correct Answer: is a straight chain paraffin ✔

Option A: has octane number of 0

Option B: has octane number of 50

Option C: has octane number of 100

Option D: is an index of detonation quality

Correct Answer: has octane number of 100 ✔

Option A: 30 – 65°C

Option B: 65 – 220°C

Option C: 220 – 350°C

Option D: 350 – 450°C

Correct Answer: 220 – 350°C ✔

Option A: octane number

Option B: cetane number

Option C: calorific value

Option D: self ignition temperature

Correct Answer: octane number ✔

Option A: less than 100°C

Option B: between 100-250°C

Option C: between 250 – 300°C

Option D: between 400 – 500°C

Correct Answer: between 250 – 300°C ✔

Option A: above the piston (/;) below the piston

Option B: between the pistons

Option C: any when

Option D: there is no such criterion

Correct Answer: between the pistons ✔

Option A: a supercharger

Option B: a centrifugal blower

Option C: a vacuum chamber

Option D: an injection tube

Correct Answer: a vacuum chamber ✔

Option A: supercharger

Option B: centrifugal pump

Option C: natural aspirator

Option D: movement of engine piston

Correct Answer: movement of engine piston ✔

Option A: flat

Option B: contoured

Option C: slanted

Option D: depressed

Correct Answer: contoured ✔

Option A: chemically correct mixture

Option B: lean mixture

Option C: rich mixture for idling

Option D: rich mixture for over loads

Correct Answer: chemically correct mixture ✔

Option A: SEA 30

Option B: SAE 4£

Option C: SAE 50

Option D: SAE 70

Correct Answer: SAE 80 ✔

Option A: controlling valve opening/closing

Option B: governing

Option C: injection

Option D: carburettion

Correct Answer: carburettion ✔

Option A: minimum temperature to which oil is heated in order to give off inflammable vapours in sufficient quantity to ignite momentarily when brought in contact with a flame

Option B: temperature at which it solidifies or congeals

Option C: it catches fire without external aid

Option D: indicated by 90% distillation temperature i.e., when 90% of sample oil has distilled off

Correct Answer: temperature at which it solidifies or congeals ✔

Option A: 9 : 1

Option B: 12 : 1

Option C: 15 : 1

Option D: 18 : 1

Correct Answer: 12 : 1 ✔

Option A: 1 : 1

Option B: 5 : 1

Option C: 10:1

Option D: 15 : 1

Correct Answer: 10:1 ✔

Option A: diesel

Option B: kerosene

Option C: fuel oil

Option D: gasoline

Correct Answer: gasoline ✔

Option A: upto 25%

Option B: upto 35%

Option C: upto 50%

Option D: upto 75%

Correct Answer: upto 100%. ✔

Option A: maximum pressure developed

Option B: minimum pressure

Option C: instantaneous pressure at any instant

Option D: exhaust pressure

Correct Answer: average pressure ✔

Option A: exhaust valve opens at 35° before bot-tom dead center and closes at 20° after top dead center

Option B: exhaust valve opens at bottom ‘dead center and closes at top dead center

Option C: exhaust valve opens just after bottom dead center and closes just before top dead center

Option D: may open and close anywhere

Correct Answer: exhaust valve opens at 35° before bot-tom dead center and closes at 20° after top dead center ✔

Option A: diesel engines

Option B: gas turbines

Option C: petrol engines

Option D: aircraft engines

Correct Answer: aircraft engines ✔

Option A: increase efficiency

Option B: increase power

Option C: reduce weight and bulk for a given out-put

Option D: effect fuel economy

Correct Answer: reduce weight and bulk for a given out-put ✔

Option A: equal to stroke volume

Option B: equal to stroke volume and clearance volume

Option C: less than stroke volume

Option D: more than stroke volume

Correct Answer: less than stroke volume ✔

Option A: higher

Option B: lower

Option C: remain unaffected

Option D: unpredictable

Correct Answer: higher ✔

Option A: piston ring and cylinder wear

Option B: formation of hard coating on piston skirts

Option C: oil sludge in the engine crank case

Option D: detonation

Correct Answer: detonation ✔

Option A: more

Option B: less

Option C: same

Option D: more/less depending on capacity of engine

Correct Answer: less ✔

Option A: same

Option B: more

Option C: less

Option D: less or more depending on operating conditions

Correct Answer: more ✔

Option A: is lighter

Option B: wears less

Option C: absorbs shocks

Option D: is stronger

Correct Answer: is lighter ✔

Option A: same

Option B: less

Option C: more

Option D: variable

Correct Answer: more ✔

Option A: larger

Option B: slowed down

Option C: smaller

Option D: liquid

Correct Answer: larger ✔

Option A: calorific value of oil

Option B: low heat value of oil

Option C: high heat value of oil

Option D: mean heat value of oil

Correct Answer: low heat value of oil ✔

Option A: fuel tank capacity

Option B: lub oil capacity

Option C: swept volume

Option D: cylinder volume

Correct Answer: swept volume ✔

Option A: kerosene

Option B: gasoline

Option C: paraffin

Option D: diesel

Correct Answer: natural gas ✔

Option A: less difficult to ignite

Option B: just about the same difficult to ignite

Option C: more difficult to ignite

Option D: highly ignitable

Correct Answer: more difficult to ignite ✔

Option A: fuel pump

Option B: governor

Option C: injector

Option D: carburettor

Correct Answer: carburettor ✔

Option A: clearance volume

Option B: volumetric efficiency

Option C: ignition time

Option D: effective compression ratio

Correct Answer: effective compression ratio ✔

Option A: vaporisation

Option B: carburetion

Option C: ionisation

Option D: injection

Correct Answer: atomisation ✔

Option A: compression starts at 35° after bottom dead center and ends at top dead center

Option B: compression starts at bottom dead center and ends at top dead center

Option C: compression starts at 10° before bottom dead center and, ends just before top dead center

Option D: may start and end anywhere

Correct Answer: compression starts at 35° after bottom dead center and ends at top dead center ✔

Option A: feeding more fuel

Option B: increasing flywheel size

Option C: heating incoming air

Option D: scavenging

Correct Answer: supercharging ✔

Option A: 2-stroke petrol engine

Option B: 4-stroke petrol engine

Option C: diesel engine

Option D: gas turbine

Correct Answer: steam turbine ✔

Option A: more

Option B: loss

Option C: same

Option D: may be more or less depending on engine capacity

Correct Answer: loss ✔

Option A: 0.15 kg

Option B: 0.2 kg

Option C: 0.25 kg

Option D: 0.3 kg

Correct Answer: 0.2 kg ✔

Option A: leaking piston rings

Option B: use of thick head gasket

Option C: clogged air-inlet slots

Option D: increase in clearance volume caused b bearing-bushing wear

Correct Answer: all of the above ✔

Option A: 80°C

Option B: 120°C

Option C: 180°C

Option D: 240°C

Correct Answer: 80°C ✔

Option A: homogeneous

Option B: heterogeneous

Option C: both A. and B.

Option D: laminar

Correct Answer: heterogeneous ✔

Option A: increase

Option B: decrease

Option C: be independent

Option D: may increase or decrease depending on other factors

Correct Answer: decrease ✔

Option A: 2%

Option B: 4%

Option C: 8%

Option D: 14%

Correct Answer: 4% ✔

Option A: 6 kg/cm

Option B: 12kg/cmz

Option C: 20 kg/cmz

Option D: 27.5 kg/cmz

Correct Answer: 35 kg/cm ✔

Option A: opens at 20° before top dead center and closes at 35° after the bottom dead center

Option B: opens at top dead center and closes at bottom dead center

Option C: opens at 10° after top dead center and closes 20° before the bottom dead center

Option D: may open or close anywhere

Correct Answer: opens at 20° before top dead center and closes at 35° after the bottom dead center ✔

Option A: speed

Option B: temperature

Option C: volume of cylinder

Option D: m.e.p. and I.H.P.

Correct Answer: m.e.p. and I.H.P. ✔

Option A: increase

Option B: decrease

Option C: remain same

Option D: unpredictable

Correct Answer: decrease ✔

Option A: net efficiency

Option B: efficiency ratio

Option C: relative efficiency

Option D: overall efficiency

Correct Answer: relative efficiency ✔

Option A: spark

Option B: injected fuel

Option C: heat resulting from compressing air that is supplied for combustion

Option D: ignition

Correct Answer: heat resulting from compressing air that is supplied for combustion ✔

Option A: same

Option B: less

Option C: more

Option D: more or less depending on power rating

Correct Answer: more ✔

Option A: yes

Option B: no

Option C: to some extent

Option D: unpredictable

Correct Answer: no ✔

Option A: air used for combustion sent under pres-sure

Option B: forced air for cooling cylinder

Option C: burnt air containing products of combustion

Option D: air used for forcing burnt gases out of engine’s cylinder during the exhaust period

Correct Answer: air used for forcing burnt gases out of engine’s cylinder during the exhaust period ✔

Option A: 1/2

Option B: 1

Option C: 2

Option D: 4

Correct Answer: 2 ✔

Option A: instantaneous and rapid burning of the first part of the charge

Option B: instantaneous atuo iginition of last part of charge

Option C: delayed burning of the first part of the charge

Option D: reduction of delay period

Correct Answer: instantaneous and rapid burning of the first part of the charge ✔

Option A: 1 valve

Option B: 2 valves

Option C: 3 valves

Option D: 4 valves

Correct Answer: 3 valves ✔

Option A: it is properly designed

Option B: best quality fuel is used

Option C: can not work as it is impossible

Option D: flywheel size is proper

Correct Answer: can not work as it is impossible ✔

Option A: uniform throughout the mixture

Option B: chemically correct mixture

Option C: about 3-5% rich mixture

Option D: about 10% rich mixture

Correct Answer: about 10% rich mixture ✔

Option A: minimum temperature to which oil is heated in order to give off inflammable vapours in sufficient quantity to ignite momentarily when brought in contact with a flame

Option B: temperature at which it solidifies or congeals

Option C: it catches fire without external aid

Option D: indicated by 90% distillation temperature, i.e., when 90% of sample oil has distilled off

Correct Answer: indicated by 90% distillation temperature, i.e., when 90% of sample oil has distilled off ✔

Option A: 0.3 kg/hr

Option B: 1 kg/hr

Option C: 3 kg/hr

Option D: 5 kg/hr

Correct Answer: 1 kg/hr ✔

Option A: 1 m3

Option B: 5 m3

Option C: 5-6 m3

Option D: 9-10 m3

Correct Answer: 9-10 m3 ✔

Option A: 8 : 1

Option B: 10 : 1

Option C: 15 : 1

Option D: 20 : 1 and less

Correct Answer: 20 : 1 and less ✔

Option A: 6 : 1

Option B: 9 : 1

Option C: 12 : 1

Option D: 15 : 1

Correct Answer: 15 : 1 ✔

Option A: thermal efficiency

Option B: speed

Option C: power output

Option D: fuel consumption

Correct Answer: power output ✔

Option A: naturally aspirated

Option B: supercharged

Option C: centrifugal pump

Option D: turbo charger

Correct Answer: supercharged ✔

Option A: minimum temperature to which1 oil is heated in order to give off inflammable vapours in sufficient quantity to ignite momentarily when brought in contact with a flame

Option B: temperature at which it solidifies or congeals

Option C: temperature at which it catches fire without external aid

Option D: indicated by 90% distillation temperature, i.e. when 90% of sample oil has distilled off

Correct Answer: minimum temperature to which1 oil is heated in order to give off inflammable vapours in sufficient quantity to ignite momentarily when brought in contact with a flame ✔

Option A: scavenging

Option B: turbulence

Option C: supercharging

Option D: pre-ignition

Correct Answer: supercharging ✔

Option A: transformer

Option B: d.c. generator

Option C: capacitor

Option D: magnetic circuit

Correct Answer: d.c. generator ✔

Option A: using additives in the fuel

Option B: engine derating i.e. reducing the maxi-mum flow of fuel

Option C: increasing the compression ratio

Option D: adherence to proper fuel specification

Correct Answer: increasing the compression ratio ✔

Option A: 1 sec

Option B: 0.1 sec

Option C: 0.01 sec

Option D: 0.001 sec

Correct Answer: 1 sec ✔

Option A: more efficient

Option B: less efficient

Option C: equally efficient

Option D: unperdictable

Correct Answer: more efficient ✔

Option A: Otto cycle

Option B: Diesel cycle

Option C: Dual cycle

Option D: Carnot cycle

Correct Answer: Dual cycle ✔

Option A: 1500 rpm

Option B: 750 rpm

Option C: 3000 rpm

Option D: any value independent of engine speed

Correct Answer: 750 rpm ✔

Option A: 2-stroke cycle engines

Option B: 4-stroke cycle engines

Option C: aeroplane engines

Option D: diesel engines

Correct Answer: high efficiency engines ✔

Option A: the friction is high

Option B: the friction is unpredictable

Option C: the small difference in cooling water temperature or in internal friction has a disproportionate effect

Option D: the engine is rarely operated

Correct Answer: the small difference in cooling water temperature or in internal friction has a disproportionate effect ✔

Option A: calorific value of oil

Option B: low heat value of

Option C: high heat value of oil

Option D: mean heat value of oil

Correct Answer: high heat value of oil ✔

Option A: increase linearly

Option B: decrease linearly

Option C: increase parabolically

Option D: decrease parabolically

Correct Answer: decrease linearly ✔

Option A: 250°C

Option B: 500°C

Option C: 1000°C

Option D: 150CPC

Correct Answer: 1000°C ✔

Option A: fuelinjection starts at 10° before to dead center and ends at 20° after tor dead center

Option B: fuel injection starts at top dead center and ends at 20° after top dead center

Option C: fuel injection starts at just before top dead center and ends just after top deac center

Option D: may start and end anywhere

Correct Answer: fuelinjection starts at 10° before to dead center and ends at 20° after tor dead center ✔

Option A: air aione

Option B: air and fuel

Option C: air and lub oil

Option D: fuel alone

Correct Answer: air aione ✔

Option A: peak pressure

Option B: rate of rise of pressure

Option C: rate of rise of temperature

Option D: peak temperature

Correct Answer: rate of rise of pressure ✔

Option A: Diesel cycle

Option B: Otto cycle

Option C: Dual combustion cycle

Option D: Special type of air cycle

Correct Answer: Dual combustion cycle ✔