Question Set 185

41.

A shaft is subjected to a maximum bending stress of 80 N/mm² and maximum shearing stress equal to 30 N/mm² at a particular section. If the yield point in tension of the material is 280 N/mm² and the maximum shear stress theory of failure is used, then the factor of safety obtained will be

A.	2.5
B.	2.8
C.	3.0
D.	3.5

Answer: Option B

42.

The longitudinal stress is __________ of the circumferential stress.

A.	one-half
B.	two-third
C.	three-fourth
D.	double

Answer: Option A

43.

The expression 0.175 - 0.841/T is the Lewis form factor for

A.	composite and full depth involute system
B.	20° full depth involute system
C.	20° stub system
D.	none of the above

Answer: Option C

44.

A screw will be self locking, if

A.	friction angle is less than helix angle
B.	friction angle is more than helix angle
C.	friction angle is equal to helix angle
D.	efficiency of screw is 100%

Answer: Option B

45.

The maximum shear stress theory is used for

A.	brittle materials
B.	ductile materials
C.	plastic materials
D.	non-ferrous materials

Answer: Option B

46.

The elasticity is the property of a material which enables it to

A.	regain its original shape after deformation when the external forces are removed
B.	draw into wires by the application of a tensile force
C.	resist fracture due to high impact loads
D.	retain deformation produced under load permanently

Answer: Option A

47.

The surface finish factor for a mirror polished material is

A.	0.45
B.	0.65
C.	0.85
D.	1

Answer: Option D

48.

For low and moderate speed engines, the cam follower should move with

A.	uniform velocity
B.	simple harmonic motion
C.	uniform accleration and retardation
D.	cycloidal motion

Answer: Option B

49.

Which of the following statement is correct ?

A.	A parallel sunk key is a taperless key
B.	A parallel sunk key may be rectangular or square in cross-section
C.	A flat saddle key is a taper key which fits in a key way of the hub and is flat on the shaft
D.	all of the above

Answer: Option D

50.

When a bolt and nut is made of mild steel, then the effective height of nut is made equal to (where d = Nominal diameter of bolt)

A.	0.5 d
B.	0.75 d
C.	d
D.	1.25 d

Answer: Option C