Machine Design MCQs

Question 1

Castle nut is a locking device in which

Accepted 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

Answer

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

Answer

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

Answer

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

Question 2

When the length of the journal is equal to the diameter of the journal, then the bearing is said to be a

Accepted Answer

Square bearing

Answer

Short bearing

Answer

Long bearing

Answer

Medium bearing

Question 3

Factor of safety for fatigue loading is the ratio of

Accepted Answer

Endurance limit to the working stress

Answer

Elastic limit to the working stress

Answer

Elastic limit to the yield point

Answer

Young's modulus to the ultimate tensile strength

Question 4

Crowning on pulley helps

Accepted Answer

To keep the belt in centre on a pulley while it is in motion

Answer

In decreasing the slip of the belt

Answer

In increasing the slip of the belt

Answer

To increase pulley life

Question 5

A bench vice has following type of threads

Accepted Answer

Buttress

Answer

Metric

Answer

Square

Answer

Acme

Question 6

Applications in which stresses are encountered in one direction only uses following type of threads

Accepted Answer

Buttress

Answer

Metric

Answer

Acme

Answer

Square

Question 7

According to Indian standard specifications, 100 H6/g5 means that the

Accepted Answer

Basic size is 100 mm

Answer

Actual size is 100 mm

Answer

Difference between the actual size and basic size is 100 mm

Answer

None of the above

Question 8

The railway carriage couplings have

Accepted Answer

Buttress threads

Answer

Square threads

Answer

Acme threads

Answer

Knuckle threads

Question 9

Gear box is used

Accepted Answer

To obtain variable speeds

Answer

To produce torque

Answer

For speed reduction

Answer

To increase efficiency of system