Machine Design MCQs

Question 1

If d is the normal diameter of a bolt in mm, then the initial tension in kg in a bolt used for making a fluid tight joint as for steam engine cover joint is calculated by the relation

Accepted Answer

168d

Answer

102d

Answer

138d

Answer

151d

Question 2

Split nut is a locking device in which

Accepted Answer

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

Answer

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

Answer

A hard fibre or nylon cotter is recessed in the nut and becomes threaded as the nut is screwed on the bolt causing-4 tight grip

Answer

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

Question 3

The function of cutting oil when threading a pipe is to

Accepted Answer

All of the above

Answer

Provide cooling action

Answer

Lubricate the dies

Answer

Help remove chips

Question 4

For tight leakage joints, following type of thread is best suited

Accepted Answer

NPT (national pipe threads)

Answer

Metric

Answer

Acme

Answer

Square

Question 5

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 splitted 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 6

When a nut is tightened by placing a washer below it the Jolt will be subjected to following type of toads

Accepted Answer

Tension

Answer

Compression

Answer

Shear

Answer

Combined loads

Question 7

If a spring is cut down into two springs, the stiffness of cut springs will be

Accepted Answer

Double

Answer

Half

Answer

Same

Answer

Unpredictable

Question 8

Aircraft body is usually fabricated by

Accepted Answer

Rivetting

Answer

Welding

Answer

Precasting

Answer

Casting

Question 9

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

Accepted Answer

Double

Answer

Half

Answer

Same

Answer

Unpredictable