Machine Design MCQs & Answers | Machine Design Quiz

81 The rated life of a bearing varies

A directly as load

B inversely as square of load

C inversely as cube of load

D inversely as fourth power of load

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Answer: inversely as cube of load

82 Oil in journal bearing should be applied at the point where load is

A nil or lightest

B maximum

C average

D any one of the above

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Answer: nil or lightest

83 In hydrostatic bearings

A the Oil film pressure is generated only by the rotation of the journal

B the oil film is maintained by supplying oil under pressure

C do not require external supply of lubricant

D grease is used for lubrication

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Answer: the oil film is maintained by supplying oil under pressure

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

A 0.01 micron

B 0.1 micron

C 1 micron

D 10 microns

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Answer: 1 micron

85 If p = bearing pressure on projected bearing area, z = absolute viscosity of lubricant, and N = speed of journal, then the bearing characteristic number is given by

A ZN/p

B p/ZN

C Z/pN

D N/Zp

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Answer: ZN/p

86 Antifriction bearings are

A ball and roller bearings

B thin lubricated bearings

C sleeve bearings

D none of the above

View Answer

Answer: none of the above

87 In hydrodynamic bearings

A the oil film pressure is generated only by the rotation of the journal

B the oil film is maintained by supplying oil under pressure

C do not require external supply of lubricant

D grease is used for lubrication

View Answer

Answer: the oil film pressure is generated only by the rotation of the journal

88 If two springs are in parallel then their overall stiffness will be

A half

B same

C double

D unpredictable

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Answer: double

89 Belt slip may occur due to

A heavy load

B loose belt

C driving pulley too small

D all of the above

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Answer: all of the above

90 Spring stiffness is

A ratio of coil diameter to wire diameter

B load required to produce unit deflection

C its capability of storing energy

D its ability to absorb shocks

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Answer: load required to produce unit deflection

91 Form coefficient of spring is

A ratio of coil diameter to wire diameter

B load required to produce unit deflection

C its capability of storing energy

D concerned With strength of wire of spring

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Answer: its capability of storing energy

92 Spring index is

A ratio of coil diameter to wire diameter

B load required to produce unit deflection

C its capability of storing energy

D indication of quality of spring

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Answer: ratio of coil diameter to wire diameter

93 Which of the following pipe joints would be suitable for pipes carrying steam

A flanged

B threaded

C bell and spigot

D expansion

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Answer: expansion

94 The piston rod of a steam engine is usually connected to the crosshead by means of

A bolted joint

B cotter joint

C universal joint

D kunckle joint

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Answer: cotter joint

95 Gear box is used

A to produce torque

B for speed reduction

C to obtain variable speeds

D to increase efficiency of system

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Answer: to obtain variable speeds

96 When a nut is tightened by plaping a washer below it, the bolt will be subjected to following type of loads

A compression

B tension

C shear

D combined loads

View Answer

Answer: tension

97 Castle nut is a locking device in which

A one smaller nut is tightened over main nut and main nut tightened against smaller one by loosening, creating friction jamming

B a slot is cut partly is middle of nut and then slot reduced by tightening a screw

C a hard fiber or nylon cotter is recessed in the nut and becomes threaded as the nut is screwed on the bolt causing a tight grip

D through slots are made at top and a cotter pin is passed through these and a hole in the bolt, and cotter pin spitted and bent in reverse direction at other end

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Answer: through slots are made at top and a cotter pin is passed through these and a hole in the bolt, and cotter pin spitted and bent in reverse direction at other end

98 The shear plane in case of bolts should

A be across threaded portion of shank

B be parallel to axis of bolt

C be normal to threaded portion of shank

D never be across the threaded portion

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