Multiple choice question for engineering
Set 1
1. In a two stroke engine, the working cycle is completed in two revolutions of the crankshaft.
a) True
b) False
Answer
Answer: b [Reason:] In a two stroke engine, the working cycle is completed in one revolution of the crankshaft.
2. A two stroke cycle engine gives _____________ the number of power strokes as compared to the four stroke cycle engine, at the same engine speed.
a) half
b) same
c) double
d) four times
Answer
Answer: c
3. A two stroke cycle engine occupies larger floor area than a four stroke cycle engine.
a) True
b) False
Answer
Answer: b [Reason:] A two stroke cycle engine occupies less floor area than a four stroke cycle engine.
4. A two stroke engine gives _____________ mechanical efficiency than a four stroke cycle engine.
a) higher
b) lower
c) equal
d) none of the mentioned
Answer
Answer: a [Reason:] As compared to a four stroke cycle engine, the mechanical efficiency of two stroke engine gives higher.
5. The two stroke cycle engine have lighter flywheel.
a) True
b) False
Answer
Answer: a
6. Thermal efficiency of a two stroke cycle engine is _____________ a four stroke cycle engine.
a) equal to
b) less than
c) greater than
d) none of the mentioned
Answer
Answer: b
7. 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 the mentioned
Answer
Answer: b [Reason:] In a petrol engine, only at the end of suction stroke, the mixture has the lowest pressure.
8. In compression ignition engines, swirl denotes a
a) haphazard motion of the gases in the chamber
b) rotary motion of the gases in the chamber
c) radial motion of the gases in the chamber
d) none of the mentioned
Answer
Answer: b [Reason:] In compression ignition engines, swirl denotes a rotary motion of the gases in the chamber as swirl is always related to rotary motion.
9. 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 atomization.
c) ensure that penetration is not high
d) all of the mentioned
Answer
Answer: d [Reason:] 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 atomization.
c) ensure that penetration is not high.
10. Which of the following engines will have heavier flywheel than the remaining ones?
a) 30 kW four stroke petrol engine running at 1500 r.p.m
b) 30 kW two stroke petrol engine running at 1500 r.p.m
c) 30 kW two stroke diesel engine running at 750 r.p.m
d) 30 kW four stroke diesel engine running at 750 r.p.m
Answer
Answer: a [Reason:] The flywheel in a four stroke petrol engine is heavier than in a two stroke petrol engine and there is no flywheel in a diesel engine.
Set 2
1. Carburetors are categorized depending upon
a) direction of flow of air
b) direction of flow of fuel
c) direction of flow of air-fuel
d) none of the mentioned
Answer
Answer: a [Reason:] Generally, carburetors are categorized depending upon direction of flow of air and not on fuel flow.
2. In updraught type carburetors, air enters at the
a) center
b) top
c) bottom
d) none of the mentioned
Answer
Answer: c [Reason:] Generally, in updraught type carburetors, air enters at the bottom and leaves at the top.
3. In updraught type carburetors, air leaves at the
a) center
b) top
c) bottom
d) none of the mentioned
Answer
Answer: b [Reason:] Generally, in updraught type carburetors, air leaves at the top and enters at the bottom.
4. In the constant choke carburetor, the air and fuel flow areas are always maintained to be
a) constant
b) variable
c) linear
d) none of the mentioned
Answer
Answer: a [Reason:] Generally, in the constant choke carburetor, the air and fuel flow areas are always maintained to be constant.
5. In the constant choke carburetor,he pressure difference that causes flow of fuel and air is kept
a) constant
b) variable
c) linear
d) none of the mentioned
Answer
Answer: b
6. Solex and Zenith carburetors are
a) constant choke carburetors
b) constant vacuum carburetors
c) multiple venturi carburetors
d) multi jet carburetors
Answer
Answer: a
7. The constant vacuum carburetor is also known as
a) constant choke carburetor
b) variable choke carburetor
c) multiple venturi carburetor
d) multi jet carburetor
Answer
Answer: b
8. In constant vacuum carburetor, air and fuel flow areas are maintained at a ____________ rate as per the demand on the engine.
a) constant
b) variable
c) linear
d) none of the mentioned
Answer
Answer: b
9. In constant vacuum carburetor, the vacuum is maintained at a ___________ rate.
a) constant
b) variable
c) linear
d) none of the mentioned
Answer
Answer: a [Reason:] In constant vacuum carburetor, the vacuum is maintained at a constant rate while air and fuel are maintained at a variable rate.
10. S.U and Carter carburetors are
a) constant choke carburetors
b) constant vacuum carburetors
c) multiple venturi carburetors
d) multi jet carburetors
Answer
Answer: b
Set 3
1. Multiple venturi system uses ____________ venturi.
a) single
b) multiple
c) double or triple
d) none of the mentioned
Answer
Answer: c [Reason:] Generally, a multiple venturi system uses double or triple venturi.
2. _____________ depression is created in the region of the fuel nozzle.
a) high
b) low
c) medium
d) none of the mentioned
Answer
Answer: a [Reason:] Generally, a high depression is created in the region of the fuel nozzle.
3. In multiple venturi system, the condensation of fuel is
a) increased
b) kept constant
c) reduced
d) none of the mentioned
Answer
Answer: c
4. In multiple venturi system, the speed system is
a) high
b) low
c) medium
d) none of the mentioned
Answer
Answer: a
5. A dual carburetor supplies ______________ quality charge of the mixture to the cylinders.
a) uniform
b) variable
c) linear
d) none of the mentioned
Answer
Answer: a [Reason:] For the practical purposes the dual carburetor supplies uniform quality charge of the mixture to the cylinders.
6. The volumetric efficiency of a dual carburetor is ________________ in a single barrel carburetor.
a) lower than
b) higher than
c) same as
d) none of the mentioned
Answer
Answer: b [Reason:] Generally, the volumetric efficiency of a dual carburetor is higher than in a single barrel carburetor.
7. Carburetors with two outlets connected to two intake manifolds are known as
a) barrel
b) two throat carburetors
c) all of the mentioned
d) none of the mentioned
Answer
Answer: c [Reason:] Carburetors with two outlets connected to two intake manifolds are known as barrel or two throat carburetors.
8. The important requirements of an automobile carburetors are
a) ease of starting the engine, particularly under low ambient conditions
b) ability to give full power quickly after starting the engine
c) equally good and smooth engine operation at various loads
d) all of the mentioned
Answer
Answer: d [Reason:] The important requirements of an automobile carburetors are
i) ease of starting the engine, particularly under low ambient conditions
ii) ability to give full power quickly after starting the engine
iii) equally good and smooth engine operation at various loads
iv) good and quick acceleration of the engine
v) developing sufficient power at high engine speeds
vi) simple and compact in construction
vii) good fuel economy
viii) absence of racing of the engine under idling conditions
ix) ensuring full torque at low speeds.
9. The important requirements of an automobile carburetors are
a) good and quick acceleration of the engine
b) developing sufficient power at high engine speeds
c) simple and compact in construction
d) all of the mentioned
Answer
Answer: d [Reason:] Same as above.
10. The important requirements of an automobile carburetors are
a) good fuel economy
b) absence of racing of the engine under idling conditions
c) ensuring full torque at low speeds.
d) all of the mentioned
Answer
Answer: d [Reason:] Same as above.
11. A soles carburetor has
a) good ease of starting
b) good performance
c) reliability
d) all of the mentioned
Answer
Answer: d [Reason:] The solex carburetor is famous for its ease of starting, good performance and reliability.
Set 4
1. The following bracket is welded to the vertical column. The joint undergoes torsional stresses.
a) True
b) False
Answer
Answer: b [Reason:] This joint undergoes bending stresses but not torsional stresses.
2. A bracket is shown welded to a vertical column by means of two fillet welds. The bending stress induced in the welds can be given by
a) My/I
b) 2My/I
c) My/2I
d) None of the listed
Answer
Answer: a [Reason:] Formula.
3. Calculate the moment of inertia about the axis parallel to welds and shift it to CG by considering thickness of welds t.
a) tᵌ+2000t
b) None of the listed
c) 250000 t
d) 125000 t
Answer
Answer: c [Reason:] I=[50tᵌ/12 + (50t)x50² ] x 2, ignoring tᵌ term.
4. Find the bending stress in the top weld is if thickness of weld is t. Given P=15kN and e=120mm.
a) 230/t
b) 360/t
c) 200/t
d) None of the listed
Answer
Answer: b [Reason:] σ=My/I or M=15000×120, y=50 and I=250000t.
5. Find the thickness of the weld is if allowable shear stress in the welds is 70N/mm². Given P=15kN and e=120mm.
a) None of the listed
b) 3.35mm
c) 4mm
d) 4.73mm
Answer
Answer: d [Reason:] σ=My/I or M=15000×120, y=50 and I=250000t,τ₁=15000/100t or 150/t. Τ=√(σ/2)²+τ₁² or 234.3/t =70 or t=3.35mm and leg=3.35/0.707.
6. The bracket welded to the vertical plate by means of two fillet welds. Calculate the bending stress in the welds if P=40kN, leg=4mm and e=400mm.
a) None of the listed
b) 34N/mm²
c) 24 N/mm²
d)44 N/mm²
Answer
Answer: b [Reason:] σ=My/I where y=250mm,I=2xtx500ᵌ/12 where t=4/.707.
7. The bracket welded to the vertical plate by means of two fillet welds. Calculate size of the welds if P=40kN, leg=4mm and e=400mm. Maximum permissible value of shear stress in the weld is 70N/mm².
a) 1.4mm
b) 1.7mm
c) 2.1mm
d) 3mm
Answer
Answer: c [Reason:] σ=My/I where y=250mm,I=2xtx500ᵌ/12 and τ₁=P/2xtx500.τ=√σ²+τ₁² or 104/t=70 and h=t/0.707.
8. While calculating bending stress in the following welded joints which of the welds moment of inertia can be neglected?
a) 1
b) None of the listed
c) Both 1 & 3
d) Both 2 & 4
Answer
Answer: b [Reason:] Moment of inertia of 1 & 3 can be neglected about their axes but while shifting it to CG, the term Al² cannot be neglected.
9. If a circular shaft is welded to the plate by means of circumferential fillet, then the shaft is subjected to torsional moment M. If throat of weld is t, then torsional shear stress is given by
a) M/2πtr²
b) M/πtr²
c) M/4πtr²
d) None of the listed
Answer
Answer: a [Reason:] Stress=Mr/J, here J=2πtrᵌ[I(xx)+I(yy)].
10. Magnetic crack detection method in the welds is destructible examination.
a) True
b) False
Answer
Answer: b
Examination: Magnetic crack detector passes magnetic waves through the sample and thus flux leakage is observed.
11. Testing the ultimate strength of the weld falls in nondestructive examination.
a) True
b) False
Answer
Answer: b [Reason:] Testing the ultimate strength leads to fracture of material and hence destructive.
Set 5
1. Which of the following is correct about series of range of speed in simple lathe?
a) Geometric progression
b) Arithmetic progression
c) Logarithmic progression
d) Harmonic progression
Answer
Answer: a [Reason:] Geometric progression is the series of numbers having common ratio. Range of speed follow geometric progression in simple lathe.
2. Which of the following is the correct basis in designing feed gear box for screw cutting?
a) Geometric progression
b) Arithmetic progression
c) Logarithmic progression
d) Harmonic progression
Answer
Answer: a [Reason:] Geometric progression is the series of numbers having common ratio. Feed gears box have ranges following geometric progression.
3. If cutting tool travel 1000mm in the direction of feed motion with work piece rotational speed of 500 rpm and feed rate of 0.2mm/rev, machining time in minutes will be
a) 2
b) 6
c) 8
d) 10
Answer
Answer: d [Reason:] Use t=L/ FN) where ‘t’ is time, ”L’ is effective length, ‘F’ is feed and ‘N’ is number of revolution per second.
4. Facing of work piece of diameter 72mm is need to be done at spindle speed of 80 rev per min at cross feed of 0.3mm/rev. The time required in minute for facing operation will be
a) 2
b) 1.5
c) 2.5
d) 3
Answer
Answer: b [Reason:] Time required for machining is given by, t=L/ FN) where ‘t’ is time, ”L’ is effective length, ‘F’ is feed and ‘N’ is number of revolution per second.
5. Compound rest swiveling method in taper turning operation is most suitable for
a) Long jobs with small taper angles
b) Short jobs with small taper angles
c) Short jobs with steep taper angles
d) Long jobs with steep taper angles
Answer
Answer: c [Reason:] Compound rest swiveling method gives less space and less revolution and hence in taper turning operation it is most suitable for Short jobs with steep taper angles.
6. In which of the following, tail stock method of taper turning operation will be preferred more?
a) Internal tapers
b) Steep tapers
c) Small tapers
d) Long slender tapers
Answer
Answer: d [Reason:] For long slender tapers, tail stock over method is most suitable because tail stock method give large space and large taper angle also.
7. Which of the followings is the correct type of threads used in lead screw having half nut in lathe which is free to rotate in both directions?
a) ACME threads
b) Buttress threads
c) Whitworth threads
d) V‐threads
Answer
Answer: a [Reason:] ACME threads have greater efficiency than other profiles of threads and hence are used in lead screw.
8. Which of the following is used to produce quality screw threads?
a) Thread casting
b) Thread cutting with single point tool
c) Thread milling ad cutting with single point tool
d) Thread chasing
Answer
Answer: d [Reason:] Quality screw threads are produced by using thread chasing, which is a very precise operation.
9. Which of the following can produce both external as well as internal threads?
a) Die threading with self‐opening die heads
b) Thread tapping with taps
c) Thread milling and multiple‐thread cutters
d) Thread chasing with multiple‐rib chasers
Answer
Answer: c [Reason:] Thread milling and multiple thread cutters are generally used for production of internal and external threads.
10. In surface finishing operation one should use a sharp tool with a ______ feed and _______ Speed of rotation of the job.
a) Minimum, minimum
b) Minimum, maximum
c) Maximum, maximum
d) Maximum, minimum
Answer
Answer: b [Reason:] Minimum feed and maximum speed of rotation gives very small material removal rate and hence used for surface finishing operation.
