Mechanical Engineering MCQs

Option A: about twice

Option B: about 0.5 times

Option C: nearly equal

Option D: about 1.7 times

Correct Answer: about 1.7 times ✔

Option A: S.I. engine

Option B: C.I. engine

Option C: both are equally good

Option D: multicylinder engine

Correct Answer: C.I. engine ✔

Option A: increases

Option B: decreases

Option C: remains unaffected

Option D: depends on other factors

Correct Answer: decreases ✔

Option A: S.I. engine

Option B: C.I. engine

Option C: two stroke engine

Option D: four stroke engine

Correct Answer: C.I. engine ✔

Option A: the shape and layout of the piston crown, the inlet port, and the valve produce the turbulent effect on fuel mixture

Option B: fuel is injected into an auxiliary chamber that is separated from the cylinder by an orifice or throat

Option C: only a part of air charge is contained in an auxiliary chamber in which the fuel starts to burn with insufficient air which due to explosion tendency mixes thoroughly into main cylinder charge

Option D: fuel is injected at atmospheric pres¬sure

Correct Answer: the shape and layout of the piston crown, the inlet port, and the valve produce the turbulent effect on fuel mixture ✔

Option A: increase the knocking tendency

Option B: decrease the knocking tendency

Option C: not affect the knocking tendency

Option D: increase or decrease knocking tendency depending on strength and time of spark

Correct Answer: increase the knocking tendency ✔

Option A: gas engine

Option B: 2-stroke S.I. engine

Option C: 4-stroke S.I. engine

Option D: steam engine

Correct Answer: 4-stroke C.I. engine ✔

Option A: 92%

Option B: 68%

Option C: 52%

Option D: 34%

Correct Answer: 34% ✔

Option A: 6 to 12 volts

Option B: 240 volts

Option C: 1000 volts

Option D: 20,000 volts

Correct Answer: 20,000 volts ✔

Option A: increase the knocking tendency

Option B: decrease the knocking tendency

Option C: not affect the knocking tendncy

Option D: increase or decrease knocking tendency depending on strenght and time of spark

Correct Answer: increase the knocking tendency ✔

Option A: ignition coil

Option B: ignition coil and distributor

Option C: ignition coil and condenser

Option D: ignition coil and contact breaker

Correct Answer: ignition coil ✔

Option A: lean mixture

Option B: theoretically correct mixture

Option C: rich mixture

Option D: any type of mixture

Correct Answer: rich mixture ✔

Option A: governor

Option B: crank shaft

Option C: gear box

Option D: flywheel

Correct Answer: flywheel ✔

Option A: same level

Option B: slightly higher level

Option C: slightly lower level

Option D: may be anywhere

Correct Answer: slightly higher level ✔

Option A: 0.85

Option B: 1

Option C: 1.1 to 1.3

Option D: 1.2 to 1.5

Correct Answer: 1 ✔

Option A: increase the knocking tendency

Option B: decrease the knocking tendecny

Option C: not affect the knocking tendency

Option D: increase or decrease knocking tendency depedning on strength and time of spark

Correct Answer: increase the knocking tendency ✔

Option A: lower than the coldest atmospheric temperature at which oil is to be pumped

Option B: higher than above

Option C: has no such relation

Option D: more than 100°C

Correct Answer: lower than the coldest atmospheric temperature at which oil is to be pumped ✔

Option A: production of highly corrosive gases corroding the cylinder walls and exhaust system

Option B: excessive engine wear

Option C: damaging of both the storage tank and the engine

Option D: deposition on engine parts

Correct Answer: deposition on engine parts ✔

Option A: rotating the crank

Option B: adjusting the spark plug gap

Option C: adjusting ignition coil position

Option D: rotating the distributor

Correct Answer: rotating the distributor ✔

Option A: 0.2 to 1.0 liter per minute per h.p.

Option B: 1 to 3 liters per minute per h.p.

Option C: 5 to 10 liters per minute per h.p

Option D: 10 to 20 liters per minute per h.p.

Correct Answer: 1 to 3 liters per minute per h.p. ✔

Option A: increases.

Option B: decreases

Option C: remains same

Option D: unpredictable

Correct Answer: decreases ✔

Option A: distribute charge, equally to all the cylinders

Option B: regulate power

Option C: feed lub oil to all moving parts

Option D: time the spark

Correct Answer: time the spark ✔

Option A: smaller

Option B: bigger

Option C: same size

Option D: dependent on other engine parameters

Correct Answer: bigger ✔

Option A: liquid fuel only

Option B: liquid fuel and air

Option C: solid fuel

Option D: solid fuel and air

Correct Answer: liquid fuel only ✔

Option A: lean mixture

Option B: chemically correct mixture

Option C: rich mixture

Option D: unpredictable

Correct Answer: rich mixture ✔

Option A: more

Option B: less

Option C: same

Option D: more upto some load and then less

Correct Answer: less ✔

Option A: keep the exhaust pipes warm

Option B: reduce formation of condenstae

Option C: reduce heat transfer to the engine room

Option D: increase engine efficiency

Correct Answer: reduce heat transfer to the engine room ✔

Option A: Lean mixture

Option B: Chemically correct fuel air ratio

Option C: Rich mixture

Option D: Unpredictable

Correct Answer: Chemically correct fuel air ratio ✔

Option A: bigger flywheel

Option B: smaller flywheel

Option C: same size flywheel

Option D: no flywheel

Correct Answer: bigger flywheel ✔

Option A: lean mixture

Option B: chemically correct mixture

Option C: rich mixture

Option D: unpredictable

Correct Answer: lean mixture ✔

Option A: forced lubrication system

Option B: splash lubrication

Option C: applying grease under pressure

Option D: wet sump method

Correct Answer: mixing about 5% lub oil with petrol ✔

Option A: 5:25:30:50

Option B: 25:35:5:35

Option C: 25:5:10:60

Option D: 40:30:15:15

Correct Answer: 25:5:35:35 ✔

Option A: air only

Option B: liquid fuel only

Option C: liquid fuel and air

Option D: supercharging

Correct Answer: liquid fuel and air ✔

Option A: decrease

Option B: increase

Option C: remain unalfected

Option D: depend on other factors

Correct Answer: increase ✔

Option A: 75 cc per min. per h.p.

Option B: 750 cc per min. per h.p.

Option C: 7500 cc per min. per h.p.

Option D: 75000 cc per min. per h.p.

Correct Answer: 75000 cc per min. per h.p. ✔

Option A: increase

Option B: decrease

Option C: remain unaffected

Option D: depend on other factors

Correct Answer: increase ✔

Option A: 1%

Option B: 5%

Option C: 0.1%

Option D: 0.01%

Correct Answer: 1% ✔

Option A: higher self ignition temperature

Option B: lower self ignition temperature

Option C: proper self ignition temperature

Option D: self ingition temperature has nothing to do with detonation

Correct Answer: higher self ignition temperature ✔

Option A: 2-stroke engine can run in any direction

Option B: In 4-stroke engine, a power stroke is obtained in 4-strokes

Option C: thermal efficiency of 4-stroke engine is more due to positive scavenging

Option D: petrol engines work on otto cycle

Correct Answer: petrol engines occupy more space than diesel engines for same power output ✔

Option A: supercharging reduces knocking in diesel engines

Option B: there can be limited supercharging in petrol engines because of detonation

Option C: supercharging at high altitudes is essential

Option D: supercharging results in fuel economy

Correct Answer: supercharging results in fuel economy ✔

Option A: programmer evaluation and review technique is event oriented

Option B: programmer evaluation and review technique is not event oriented

Option C: critical path method is event oriented

Option D: critical.path method is not activity oriented

Correct Answer: none of the above ✔

Option A: an activity of the project is denoted by an arrow on the net work

Option B: the tail of the arrow indicates the start of the activity

Option C: the head of the arrow indicates the end of,the activity!

Option D: the arrows are drawn (to scale from) left to right

Correct Answer: the arrows are drawn (to scale from) left to right ✔

Option A: the float may be positive, zero or negative

Option B: if the float is positive and the activity is delayed by a period equal to its total float, the completion of project in not delayed

Option C: if the float of an activity is negative, delay in its performance is bound to delay the completion of project

Option D: if the float of an activity is zero, the activity is critical and any delay in its performance will delay the whole project

Correct Answer: all of the above ✔

Option A: critical path method is an improvement upon bar chart method

Option B: critical path method provides a realistic approach to the daily problems

Option C: critical path method avoids delays which are very common in bar chart

Option D: critical path method was invented by Morgan R. Walker of Dupot and James E. Kelley of Remington U.S.A in 1957

Correct Answer: all of the above ✔

Option A: All the irreversible engines have same efficiency

Option B: All the reversible engines have same efficiency

Option C: Both Rankine and Caront cycles have same efficiency between same temperature limits

Option D: All reversible engines working between same temperature limits have same-efficiency

Correct Answer: All reversible engines working between same temperature limits have same-efficiency ✔

Option A: Thermal efficiency of diesel engine i about 34%

Option B: Theoretically correct mixture of air am petrol is approximately 15 : 1

Option C: High speed compression engines operate on dual combustion cycle

Option D: Diesel engines are compression ignition engines

Correct Answer: S.I. engines are quality-governed engines ✔

Option A: 10%

Option B: 5%

Option C: 1%

Option D: 0.1%

Correct Answer: 1% ✔

Option A: 15-20%

Option B: 20-25%

Option C: 25-30%

Option D: 30-35%

Correct Answer: 30-35% ✔

Option A: 1-3-6-5-2-4

Option B: 1-4-2-5-6-3

Option C: 1-6-2-5-4-3

Option D: 1-5-2-6-3-4

Correct Answer: 1-5-3-4-2-6 ✔

Option A: increase

Option B: decreae

Option C: be unaffected

Option D: depend on other factors

Correct Answer: increase ✔

Option A: varying compression ratio

Option B: using lian mixture

Option C: retarding the spark timing

Option D: reducing the r.p.m.

Correct Answer: retarding the spark timing ✔

Option A: 1

Option B: 0.7

Option C: 0.85

Option D: 0.5

Correct Answer: 0.85 ✔

Option A: 1-2-3-4

Option B: 1-3-2-4

Option C: 1-4-2-3

Option D: 1-2-4-3

Correct Answer: 1-3-2-4 ✔

Option A: 0°C

Option B: – 10°C

Option C: 10°C

Option D: less than – 30°C

Correct Answer: 0°C ✔

Option A: 5

Option B: 7

Option C: 10

Option D: 13

Correct Answer: 7 ✔

Option A: octane number

Option B: cetane number

Option C: calorific value

Option D: carbon content

Correct Answer: cetane number ✔

Option A: auto ignition

Option B: preignition

Option C: retarded ignition

Option D: accelerated ignition

Correct Answer: preignition ✔

Option A: instantaneous auto-ignition of last part of charge to be burnt

Option B: improper mixing of air and fuel

Option C: improper combustion

Option D: self ignition temperature has nothing to do with detonation

Correct Answer: instantaneous auto-ignition of last part of charge to be burnt ✔

Option A: enhanced by increasing compression ratio

Option B: enhanced by decreasing compression ratio

Option C: unaflected by compression ratio

Option D: first enhanced by increasig compression ratio upto a limit beyond which it will be suppressed

Correct Answer: enhanced by decreasing compression ratio ✔

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 pluger starts to pump fuel

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

Option D: time corresponding to actual ignition and top dead center

Correct Answer: time before actual fuel injection and the pump pluger starts to pump fuel ✔

Option A: 1%

Option B: 0.5%

Option C: 0.1%

Option D: 0.01%

Correct Answer: 1% ✔

Option A: not true

Option B: true at full load

Option C: true at part load

Option D: true at both part and full load

Correct Answer: true at both part and full load ✔

Option A: low temperature

Option B: low density

Option C: long ignition delay

Option D: rich mixture

Correct Answer: all of the above ✔

Option A: high temperature

Option B: high density

Option C: short delay

Option D: reactive mixture

Correct Answer: all of the above ✔

Option A: reduce cost

Option B: improve surface finish

Option C: prevent clogging

Option D: reduce wear and eliminate scuffing

Correct Answer: reduce wear and eliminate scuffing ✔

Option A: reduce weight

Option B: conduct heat efficiently

Option C: reduce possibility of scoring

Option D: reduce friction

Correct Answer: reduce possibility of scoring ✔

Option A: V-type

Option B: In-line

Option C: Vertical

Option D: Horizontal

Correct Answer: Horizontal ✔

Option A: compression ring

Option B: oil ring

Option C: scrapper ring

Option D: groove ring

Correct Answer: compression ring ✔

Option A: cast iron

Option B: aluminium

Option C: phosphor bronze

Option D: babbitt

Correct Answer: cast iron ✔

Option A: compact design requiring lesser space

Option B: improved distribution of air to cylinder

Option C: casting less liable to distortion

Option D: reduced torsional vibration because of shorter crankshaft

Correct Answer: less overhead clearance ✔

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: differential piece rate system

Option B: Rowan plan

Option C: Emerson plan

Option D: Taylor plan

Correct Answer: Taylor plan ✔

Option A: a differential piece rate system should exist

Option B: minimum wages should be guaranteed

Option C: provide incentive to group efficiency performance

Option D: all standards should be based on optimum standards of production

Correct Answer: all standards should be based on time studies ✔

Option A: HA

Option B: HA + (S~A) HA

Option C: HA + ^^-H

Option D: HA + ^^-H

Correct Answer: HA ✔

Option A: those items which consume money

Option B: those items which are not readily available

Option C: those x items which are in more demand

Option D: those items which consume more money

Correct Answer: those items which consume more money ✔

Option A: operation research

Option B: linear programming

Option C: network analysis

Option D: queuing theory

Correct Answer: linear programming ✔

Option A: iron and steel

Option B: food processing

Option C: oil and chemical

Option D: banking

Correct Answer: all of the above ✔

Option A: ordering procedure

Option B: forecasting sales

Option C: production planning

Option D: despatching and expediting

Correct Answer: ordering procedure ✔

Option A: sinking fund method

Option B: straight line method

Option C: A-B-C charging method

Option D: annuity charging method

Correct Answer: annuity charging method ✔

Option A: annual cost method

Option B: rate of return method

Option C: total life average method

Option D: present worth method

Correct Answer: any one of the above ✔