Machine Design 1 (Terms OT)

Question 1

Poisson’s ratio for steel varies

Answer 1

0.25-0.33

Question 2

The ratio of the load on a spring to its corresponding axial deflection.

Answer 2

spring scale

Question 3

The irregularity in the stress distribution caused by abrupt changes of form

Answer 3

stress raiser

Question 4

Based on ASME Code, the strength of a shaft with a keyway is almost reduced to as much as

Answer 4

75%

Question 5

A square-threaded jack has a lead angle of λ. The jack will not be self-locking when the coefficient of friction (f) is

Answer 5

f<tan λ

Question 6

Slenderness ratio is the ratio of

Answer 6

effective length of column to least radius of gyration of the column

Question 7

Transmission shaft driven by the prime mover.

Answer 7

line shaft

Question 8

The ratio of the ultimate stress or yield stress of a material to the design stress is known as

Answer 8

factor of safety

Question 9

The stress concentration factor when a machine member with stress raiser is subjected to compression is approximately

Answer 9

1.0

Question 10

A stress which varies from a minimum value to a maximum value of the same nature (ie. tensile or compressive) is called

Answer 10

varying stress

Question 11

When helical compression spring is cut into three, the stiffness of the resulting spring will be

Answer 11

three times

Question 12

Hooke’s law holds good up to

Answer 12

elastic limit

Question 13

The modulus of elasticity for shear for mild steel is approximately equal to

Answer 13

80 GPa

Question 14

The ratio of linear stress to linear strain within the proportional limit is called

Answer 14

Modulus of elasticity

Question 15

The Young’s modulus for mild steel is approximately equal to

Answer 15

210 GPa

Question 16

It is the stress at which the stress-strain curve begins to deviate from the straight line.

Answer 16

elastic limit

Question 17

When a hole of diameter ‘d’ is punched in a metal of thickness ‘t’, then the force required to punch a hole is equal to

Answer 17

πdtSu

Question 18

In torsion, the minimum stress happens at

Answer 18

the centroidal axis

Question 19

Two shafts A and B are made of the same material. The diameter of the shaft A is thrice as that of shaft B. The power transmitted by the shaft A will ……. of shaft B.

Answer 19

twenty seven times

Question 20

In the stress analysis of thin-walled cylindrical pressure vessels, the hoop stress is ……. of the longitudinal stress

Answer 20

twice

Question 21

It is a standard thread which has an included angle of 60°.

Answer 21

Metric thread

Question 22

What is the approximate solid height for a compression helical spring with ground ends?

Answer 22

NcDw

Question 23

A type of end fixity where the end of the column is guided so that it cannot sway from side to side, but offers no resistance to rotation of the end.

Answer 23

pinned-end

Question 24

For a rectangular cross-section with width ‘b’ and height ‘h’ and ‘h’>’b’, the lesser radius of gyration is

Answer 24

0.289b

Question 25

Which of the following thread is not used for power transmission in either direction?

Answer 25

Buttress thread

Question 26

Maximum Shear Stress theory is generally used for

Answer 26

ductile materials

Question 27

A load that varies from a certain minimum to a certain maximum having different magnitudes between limits and with different directions of application.

Answer 27

fluctuating load

Question 28

When a machine member is subjected to the action of two equal and opposite couples acting in parallel planes, then the machine member is said to be subjected to

Answer 28

none of the above

Question 29

Failure of a material is called fatigue when it fails

Answer 29

below the yield point