550+ Machine Design Solved MCQs

101.

If two gears having 24 and 96 teeth mesh each other, they must have been cut

A. On same setting in a machine
B. With same cutter
C. With cutters of same moduic
D. With the one cutter
E. With cutter of same diameter as that of gear
Answer» C. With cutters of same moduic
102.

The following type of mechanism is not possible in any framed structure as an independent mechanism

A. Joint mechanism
B. Increasing the diameter of threaded portion
C. Cable mechanism
D. Beam mechanism
E. Panel (sway) mechanism
Answer» A. Joint mechanism
103.

A solid shaft and a hollow shaft are to be of equal strength in torsion. The hollow shaft is to be 10% larger in diameter than the solid shaft. The ratio of the weight of the hollow shaft will be (both shafts being made of same material)

A. 1.2
B. 0.47
C. 2
D. 0.6
E. 1
Answer» C. 2
104.

The maximum size of the fillet weld that can be used is

A. Increasing the diameter of threaded portion
B. 3 mm
C. 7 mm
D. 1 mm
E. 5 mm
Answer» B. 3 mm
105.

Spring driven watches and clocks utilise

A. Hypocycloid gears
B. Epicycloid gears
C. Involute gears
D. Cycloid gears
E. Any of the above
Answer» D. Cycloid gears
106.

The shape or form factor is introduced in the design of compression members to represent the effect of

A. Increasing the diameter of threaded portion
B. vertical buckling
C. local buckling
D. diagonal buckling
E. post buckling
Answer» C. local buckling
107.

The plastic design of steel structures which is based on upper bound theorem is

A. safe, unsafe
B. Increasing the diameter of threaded portion
C. unsafe, unsafe
D. safe, safe
E. unsafe, safe
Answer» E. unsafe, safe
108.

Poisson's ratio for rubber is taken as

A. 0.1
B. 1
C. Zero
D. 2
E. 0.5
Answer» E. 0.5
109.

In above problem the cone pitch angle of the pinion will be

A. sin-1 2.0
B. cos-1 0.5
C. tan-1 0.5
D. sin-1 0.5
E. tan-1 2.0
Answer» D. sin-1 0.5
110.

Cycloidal profile gears are used in

A. Machine tools
B. Automobiles
C. Toys
D. Watches and clocks
E. Aircraft
Answer» D. Watches and clocks
111.

The ratio of lateral strain to linear strain is

A. Cast steel
B. Stress ratio
C. Factor of safety
D. Poisson ratio
E. Strain ratio
Answer» D. Poisson ratio
112.

In case of worm and worm wheel drives, the axes of the two are

A. parallel and intersecting
B. non-parallel and intersecting
C. parallel and non-intersecting
D. non-parallel and non-intersecting
E. Increasing the diameter of threaded portion
Answer» D. non-parallel and non-intersecting
113.

A close coiled helical spring is compressed. Its wire is subjected to

A. Torque
B. Shear
C. Tension
D. Biaxial
E. Compression
Answer» C. Tension
114.

The plastic design of a structure based on which of the following is always safe?

A. Mechanism method of analysis
B. Statistical method of plastic analysis
C. Upper bound theorem of plastic analysis
D. All of the above
E. Increasing the diameter of threaded portion
Answer» B. Statistical method of plastic analysis
115.

In the case of ball bearings the contacting areas between balls and running tracks are

A. circular
B. parabolic
C. elliptical
D. none of the above
E. Cast steel
Answer» C. elliptical
116.

The notch angle of Izod impact test specimen is

A. 20?
B. 22
C. 45?
D. 30?
E. 10?
Answer» C. 45?
117.

Scraping of lathe bed helps in

A. lubrication
B. increasing friction
C. Increasing the diameter of threaded portion
D. reducing friction
E. firm grip between parts
Answer» A. lubrication
118.

In an inverted tooth chain the included angle between the outer faces of the teeth?

A. 40 to 55
B. 35 to 45
C. 60 to 75
D. Increasing the diameter of threaded portion
E. 75 to 85
Answer» C. 60 to 75
119.

The value of yield stress for structural steel is about

A. Increasing the diameter of threaded portion
B. 3600 kg/cm2
C. 1600 kg/cm2
D. 4600 kg/cm2
E. 2600 kg/cm2
Answer» E. 2600 kg/cm2
120.

A warm gear is generally made of

A. Mild steel
B. Forged steel
C. Cast iron
D. Aluminium
E. None of the above
Answer» C. Cast iron
121.

The diameter of rivets for 20 mm thick plates would be

A. 10 mm
B. 20 mm
C. 15 mm
D. 40 mm
E. 30 mm
Answer» D. 40 mm
122.

The ratio of the plastic moment capacity to the yield moment capacity of a rolled steel beam section is about

A. 1.85
B. Increasing the diameter of threaded portion
C. 1.15
D. 1.55
E. 1
Answer» C. 1.15
123.

Which pair of gears usually has high friction losses?

A. All have equal frictional loss
B. Spur gears
C. Bevel gears
D. Helical gears
E. Worm and worm wheel
Answer» E. Worm and worm wheel
124.

In plastic analysis, the shape factor of a triangular section is

A. 1.15
B. Increasing the diameter of threaded portion
C. 2.34
D. 1.5
E. 1.85
Answer» C. 2.34
125.

In case of quadruple riveted butt joints the joint efficiency is usually assumed in the range

A. 40-50%
B. 50-60%
C. 85-95%
D. 75-85%
E. 60-75%
Answer» C. 85-95%
126.

A V-belt having B section is generally used when the power to be transmitted is in the range

A. 25-35 HP
B. 35-50 HP
C. 50-75 HP
D. 75-100 HP
E. 3-25 HP
Answer» E. 3-25 HP
127.

In which of the following gears the lowest degree of accuracy can be expected

A. Machine tools
B. Aeroplane gears
C. Farm machinery
D. Automobile gears
E. Reduction gears for turbines
Answer» C. Farm machinery
128.

Induction motors are generally provided with

A. Mitchel's thrust bearings
B. Sleeve bearings
C. Ball or roller bearings
D. Magnetic bearings
E. Bush bearings
Answer» C. Ball or roller bearings
129.

Which of the following gears are free from axial thrust?

A. Worm gears
B. Spiral gears
C. Helical gears
D. Bevel gears
E. Herringbone gears
Answer» E. Herringbone gears
130.

The phenomenon of eloggation and contraction of the belt is known as

A. Plasticity
B. Creep
C. Fatigue
D. Elasticity
E. Slip
Answer» B. Creep
131.

Rankine theory is applied to

A. bruite materials
B. Increasing the diameter of threaded portion
C. plastic materials
D. tough materials
E. ductile materials
Answer» A. bruite materials
132.

The clamping nut of the turn buckle has

A. Left hand threads
B. Right hand threads
C. Right hand threads on one side and left hand threads on the other side
D. Has no threads
E. None of the above
Answer» C. Right hand threads on one side and left hand threads on the other side
133.

Helical springs are not subjected to

A. Torsional shear stress
B. Transverse shear stress
C. Deflection
D. Hoop stress
E. Force
Answer» D. Hoop stress
134.

The uniform rate of descent is maintained by a brake on the drum which applies the necessary torque of 300 kg-m what additional brake torque is required to bring the system to rest in 0.50 second?

A. 6235 N-m
B. 1027 N-m
C. 2054 N-m
D. 1580 N-m
E. Increasing the diameter of threaded portion
Answer» C. 2054 N-m
135.

The part of the tooth which lies between the pitch and dedendum circle is known as

A. Base
B. Face
C. Profile
D. Root
E. Flank
Answer» E. Flank
136.

Total strain energy theory for the failure of a material at elastic limit is also known as

A. Increasing the diameter of threaded portion
B. Von mises theory
C. Rankine's theory
D. Haig's theory
E. Gust's or Treasca's theory
Answer» B. Von mises theory
137.

A solid shaft of 100 mm diameter transmits 100 HP at (450/?) r.p.m. The torque in kg-m on the shaft would be

A. 250
B. 375
C. 500
D. 990
E. 750
Answer» C. 500
138.

Stone crusher rolls are generally made of

A. Mild steel
B. Grey iron
C. Cast iron
D. Cast steel
E. High carbon steel
Answer» E. High carbon steel
139.

The 'crowning' of flat pulleys is generally done

A. To rduce the belt friction
B. To prevent belt joint from damaging the belt surface
C. To prevent the belt from running off the pulley
D. In case of cross belt drives only
E. None of the above
Answer» C. To prevent the belt from running off the pulley
140.

Piston rings are usually made of

A. Stainless steel
B. Cast iron
C. Increasing the diameter of threaded portion
D. Aluminium
E. High carban steel
Answer» B. Cast iron
141.

The main difference between rigid and flexible coupling for shafts transmitting power is

A. the number of coupling bolts are more in flexible coupling than in rigid coupling
B. a flexible element is inserted around coupling bolts in one of the flanges
C. There is a protective flange over bolts in the case of flexible coupling
D. none of the above
E. Cast steel
Answer» B. a flexible element is inserted around coupling bolts in one of the flanges
142.

Teflon is used for bearings

A. When low coefficient of friction is desired
B. Heat dissipation is a problem
C. Space is the major consideration
D. Increasing the diameter of threaded portion
E. When bearings operate at very high rpm
Answer» A. When low coefficient of friction is desired
143.

In case of a Saddle key

A. The key is welded to shaft
B. The key way is cut in shaft only
C. The key ways is cut in hub only
D. The key way is cut in both shaft and hub
E. The key is made of flexible material
Answer» C. The key ways is cut in hub only
144.

For determination of allowable stress in axial compression, IS : 800-1962 has adopted

A. Euler's formula
B. Secant formula
C. Increasing the diameter of threaded portion
D. Perry Robertson formula
E. Rankines formula
Answer» B. Secant formula
145.

Braking system on earth moving machinery is

A. Vacuum braking
B. Pneumatic braking
C. Hydraulic braking
D. Regenerative braking
E. Mechanical braking
Answer» C. Hydraulic braking
146.

In a butt welded joint, the size of weld is

A. 0.5 times the throat of weld
B. double the throat of weld
C. Increasing the diameter of threaded portion
D. equal to the throat of weld
Answer» A. 0.5 times the throat of weld
147.

The shape factor of an isosceles triangle for bending about the axis parallel to the base is

A. 2.74
B. Increasing the diameter of threaded portion
C. 2.34
D. 1.44
E. 1.74
Answer» C. 2.34
148.

A pivoted segment type thrust bearing is used in order to provide

A. Uniform wear
B. A converging film of oil
C. Balanced lead
D. Uniform frictional forces
E. Uniform velocity
Answer» B. A converging film of oil
149.

The pitch of threads on a lock-nut is

A. Fine
B. Very fine
C. Coarse
D. Same as that of nut
E. None of the above
Answer» D. Same as that of nut
150.

Aircraft body is

A. Welded structure
B. Riveted structure
C. Cast structure
D. Precast structure
E. None of the above
Answer» B. Riveted structure
151.

The weakest plane in a fillet weld is

A. the throat
B. smaller of the sides
C. side normal to the force
D. side parallel to the force
E. Increasing the diameter of threaded portion
Answer» A. the throat
152.

The holes in plates for reveting are usually made by

A. Arc cutting
B. Oxyacetylene flame
C. Punching
D. Drilling
E. Any of the above
Answer» D. Drilling
153.

Which of the following treatment is often recommended for parts operating under corrosive conditions?

A. strain-aging
B. tempering
C. normalising
D. all of the above
E. Increasing the diameter of threaded portion
Answer» B. tempering
154.

A material is generally classified as brittle if the percentage elongation (in a gauge length of 50 mm) is less than

A. Chrome steel
B. 1%
C. 2%
D. 5%
E. 15%
Answer» D. 5%
155.

A flange coupling is

A. Used for non-collinear shafts
B. Used for collinear shafts
C. Flexible
D. Used only on small shafts rotating at slow speeds
E. None of the above
Answer» B. Used for collinear shafts
156.

Splines are used when

A. Axial relative motion between shaft and hub is necessary
B. The torque is high
C. The power to be transmitted is high
D. rpm are high
E. The power to be transmitted is low
Answer» A. Axial relative motion between shaft and hub is necessary
157.

Bolts in structures are often tightened upto or beyond the yield point because

A. frction is more beyond yield point thus providing a firm joint
B. temperature variations may loosen the joint
C. it improves endurance strength
D. all of the above
E. Increasing the diameter of threaded portion
Answer» C. it improves endurance strength
158.

A triple threaded worm has a pitch diameter of 100 mm and an axial pitch of 22 mm. The lead angle will be

A. tan-1 0.21
B. tan-1 0.66
C. tan-1 0.22
D. tan-1 0.3
E. tan-1 0.36
Answer» A. tan-1 0.21
159.

Spigot and socket joints are used on pipes

A. Which are buried underground
B. Carrying air at pressure above atmospheric pressure
C. Carrying steam under high pressure
D. Carrying high pressure fluids under high pressure
E. Carrying air at pressure below atmospheric pressure
Answer» A. Which are buried underground
160.

In a compression test the fracture in cast iron specimen would occur along

A. An oblique plane
B. Along the axis of the load
C. At right angles to the specimen axis
D. Fracture will not occur in cast iron
E. None of the above
Answer» A. An oblique plane
161.

If the allowable shear stress is 960 kg/sq. cm for the size h cm, the allowable force per cm of weld length would be

A. 670 h
B. 475 h
C. 315 h
D. 400 h
E. 950 h
Answer» A. 670 h
162.

In case of a knuckle joint the pin is likely to fail in

A. Tension
B. Crushing
C. Double shear
D. Compression
E. Shear
Answer» C. Double shear
163.

Shot peening leaves the material surface in

A. residual tensile stress
B. residual shear stress
C. residual compressive stress
D. All of the above
E. Increasing the diameter of threaded portion
Answer» C. residual compressive stress
164.

A Babbit is

A. A gadget for measuring volume
B. A measure of magnetic induction produced in a material
C. A eutectic of iron and iron phosphide
D. None of these
E. Antimony bearing lead or tin alloy
Answer» E. Antimony bearing lead or tin alloy
165.

Low pressure angle on gears results in

A. Weaker teeth
B. stronger teeth
C. abrasive wear
D. none of the above
E. Cast steel
Answer» A. Weaker teeth
166.

An eye bolt is generally provided on

A. Furnaces
B. Bench vices
C. Electric motors
D. Overhead cranes
E. All of the above
Answer» C. Electric motors
167.

The satisfactory method of reclaiming worn out and under sized part subject to fatigue loads is

A. Repainting
B. Polishing
C. Electroplating
D. Recasting
E. None of the above
Answer» C. Electroplating
168.

The usual clearance provided in hydrodynamic bearing per mm of diameter of shaft is

A. 1 micron
B. 10 micron
C. 0.01 micron
D. 0.1 micron
E. 100 micron
Answer» A. 1 micron
169.

Dead weight type safety valve is not used on locomotives because

A. It is costly
B. It is susceptible to vibratory forces
C. It is not reliable
D. It is bulky
E. It gives bad apparatus
Answer» B. It is susceptible to vibratory forces
170.

Extrafine threaded connections are generally recommended for

A. Increasing the diameter of threaded portion
B. Rolled sections
C. hardened objects
D. thin walled assemblies
E. Tapped hole in castings
Answer» D. thin walled assemblies
171.

A square key is

A. Equally strong in shear and compression
B. Very weak in shear
C. Less strong in shear and more strong in compression
D. More strong in shear and less strong in compression
E. Very weak in compression
Answer» A. Equally strong in shear and compression
172.

A steel specified as St 50 will have a tensile strength of approximately

A. 50 tonnes/m2
B. 50 kg/mm2
C. 50 kg/cm2
D. 50 tonnes/mm2
E. None of the above
Answer» B. 50 kg/mm2
173.

The chain used in motor cycles is generally

A. Ewast type
B. Silent type
C. Double roller type
D. Bush roller type
E. Pintle type
Answer» B. Silent type
174.

In gear design, addendum is equal to

A. Cast steel
B. Twice of module
C. One and a half times module
D. Module
E. Half of module
Answer» D. Module
175.

Lubricant is not required in

A. Increasing the diameter of threaded portion
B. Electromagnetic bearing
C. Hydrostatic bearings
D. Gas bearings
E. Foil bearing
Answer» B. Electromagnetic bearing
176.

A connecting rod in an IC Engine is to be designed against buckling. The end conditions considered are

A. Both the ends fixed
B. Both the ends are free
C. Both the ends are hinged
D. none of the above
E. Cast steel
Answer» C. Both the ends are hinged
177.

A ball bearing cannot be provided for

A. Big ends of connecting rods for I.C. engines
B. Variable load shafts
C. Variable speed shafts
D. Automobile gear shafts
E. Low speed shafts
Answer» A. Big ends of connecting rods for I.C. engines
178.

Which of the following drive has accurate speed ratio?

A. Flat cross-belt drive
B. Timing belt drive
C. V-belt 'C' section drive
D. V-belt 'B' section drive
E. Increasing the diameter of threaded portion
Answer» B. Timing belt drive
179.

Under which condition a material ordinatily said to be ductile undergoes a fracture similar to that of a brittle material

A. Cyclic loading at normal temperature
B. Long time static loading at elevated temperature
C. Impact loading specially at low temperatures
D. All of the above
E. None of the above
Answer» D. All of the above
180.

When minimum axial thrust is the criteria, the choice of gears would been

A. Helical gears
B. Hypoid gears
C. Herringbone gears
D. Worm gears
E. None of the above
Answer» C. Herringbone gears
181.

A compressed air cylinder carries approximately 70 kg/cm2 pressure at the time of delivery. The inside diameter is 25 cm. If the steel has a yield point of 2300 kg/sq cm and a safety factor of 2.5 the wall thickness should be

A. 10 mm
B. 15 mm
C. 8 mm
D. 12 mm
E. 5 mm
Answer» A. 10 mm
182.

If during operation a boiler bursts, the matter should be reported to

A. State Government
B. Management
C. Central Government
D. Boiler inspector
E. Police
Answer» D. Boiler inspector
183.

The compression members tend to buckle in the direction of

A. Axis of load
B. Perpendicular to the axis of load
C. Minimum cross-section
D. Least radius of gyration
E. None of the above
Answer» D. Least radius of gyration
184.

A concrete wall generally

A. Absorbs and transmits sound
B. Reflects sound
C. Transmits sound
D. Absorb sound
E. Creates sound
Answer» B. Reflects sound
185.

When the bolt is subjected to shock loading the resilience of the bolt should be considered in order to prevent breakege at

A. Anywhere
B. Shank
C. Threaded portion
D. Head
E. Transition between head and shank
Answer» C. Threaded portion
186.

Maximum efficiency expected in case of single mech supr gears is around

A. 58%
B. 98%
C. 88%
D. 68%
E. 78%
Answer» B. 98%
187.

In a gas turbine rotor a radial stress of 300 kg/sq cm tensile and 500 kg/sq cm tangential stress have been found at a point. The maximum shear stress at this point would be

A. 500 kg/cm2
B. 250 kg/cm2
C. 595 kg/cm2
D. 750 kg/sq-cm
E. 300 kg/cm2
Answer» B. 250 kg/cm2
188.

The life of ball bearings as listed in catalogue represents

A. 25% survival rate
B. 90% survival rate
C. 50% survival rate
D. 75% survival rate
E. Increasing the diameter of threaded portion
Answer» B. 90% survival rate
189.

Rinkine-Gordon formula for buckling load is adopted for columns having slenderness ratio between

A. 50 and 100
B. 30 and 50
C. 10 and 30
D. 120 and 200
E. Increasing the diameter of threaded portion
Answer» D. 120 and 200
190.

Jaw clutches

A. cause shock loads when engaging
B. get disengaged at high rpm
C. get disengaged in reverse direction
D. are friction clutches which generate heat when enegaged
E. Increasing the diameter of threaded portion
Answer» A. cause shock loads when engaging
191.

A rack is a gear

A. With infinite diametral pitch
B. With infinite pitch circle diameter
C. With infinite module
D. With infinite number of teeth
E. With infinite circular pitch
Answer» D. With infinite number of teeth
192.

Expansion joints are provided on pipes carrying

A. Viscous fluids
B. Water
C. Air at pressures below atmospheric pressure
D. Steam
E. Air at high pressures
Answer» D. Steam
193.

The advantage of needle roller bearing over ball bearing is

A. Less friction
B. Less area requirement
C. Smooth operation
D. Large ratio of load capacity to size
E. None of the above
Answer» D. Large ratio of load capacity to size
194.

A V-belt designated as C 120 will have

A. 120 mm as the dia of small pulley
B. 120 cm as the length of belt
C. 120 inch as the length of belt
D. 120 cm as the centre distance between pulleys
E. None of the above
Answer» C. 120 inch as the length of belt
195.

Dielectric strength of a material is

A. Capacity to withstand high voltage
B. Capacity to resist flow of current
C. Capacity to take variable stresses
D. Energy storage capacity
E. Magnetic property
Answer» A. Capacity to withstand high voltage
196.

According to IS 800, the lacing bars should resist a transverse shear equal to

A. 7.50%
B. 2.50%
C. Increasing the diameter of threaded portion
D. 17.50%
E. 12.50%
Answer» B. 2.50%
197.

The bunkers are the containers in which the plan of rupture intersects

A. the opposite face (wall) near the bottom
B. Increasing the diameter of threaded portion
C. the opposite face (wall) near the top
D. the bottom surface of material stored
E. the top surface of material stored
Answer» E. the top surface of material stored
198.

Laser treatment of components increases fatigue resistance of metals by

A. compressing holes
B. filling vacancies
C. freezing discontinuities
D. none of the above
E. Increasing the diameter of threaded portion
Answer» C. freezing discontinuities
199.

Failure of rolling bearings occurs mainly due to

A. lubrication failure
B. fatigue
C. load and deformation
D. Increasing the diameter of threaded portion
E. plastic deformation
Answer» B. fatigue
200.

In elevated circular steel tanks, conical bottoms are attached when

A. Increasing the diameter of threaded portion
B. water is alkaline
C. water is oily
D. water is acidic
E. water is muddy
Answer» E. water is muddy
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