Machine Design MCQs

Question 1

In stroboscopic measurement, a disc having one mark was seen to have two similar marks at 40 cps signal. Its speed is

Accepted Answer

1200 r.p.m.

Answer

600 r.p.m.

Answer

2400 r.p.m.

Answer

4800 r.p.m.

Question 2

An involute gear should have minimum of

Accepted Answer

8 teeth

Answer

12 teeth

Answer

16 teeth

Answer

20 teeth

Question 3

In order to avoid interference for 20° pressure angle teeth, minimum number of teeth should be

Accepted Answer

More than 11

Answer

12

Answer

18

Answer

Less than 18

Question 4

Value of Wahl stress factor K for springs with increase in value of C

Accepted Answer

Decreases exponentially

Answer

Decreases linearly

Answer

Increases linearly

Answer

Remains same

Question 5

Which is correct statement (Fatigue cracks can spread only by)

Accepted Answer

Tensile stress (and not by compressive or shear) and in directions perpendicular to the tensile stress

Answer

Tensile stress and in direction along the tensile stress

Answer

Compressive and shear stresses

Answer

Any of the three types of stresses

Question 6

Concentric helical springs should be

Accepted Answer

Wound with opposite hand helices

Answer

Wound in same direction

Answer

Could be wound in any direction

Answer

Direction of winding depends on the load to be carried

Question 7

Allowable stresses in compression springs for most of the materials with increase in size of wire will

Accepted Answer

Decrease

Answer

Increase

Answer

Remain same

Answer

Unpredictable

Question 8

Which is true statement about Belleville springs

Accepted Answer

These are composed of coned discs which may be stacked up to obtain variety of load-deflection characteristics

Answer

These are used for dynamic loads

Answer

These are commonly used in clocks and watches

Answer

These take up torsional loads

Question 9

A shaft subjected to combined bending and torsion can be designed by following stress theory

Accepted Answer

Maximum normal stress theory

Answer

Maximum shear stress theory

Answer

Maximum resultant stress theory

Answer

All of the above