Question Set 190

41. 

The contact ratio is the ratio of

A.

length of path of contact to the circular pitch

B.

length of arc of contact to the circular pitch

C.

length of arc of approach to the circular pitch

D.

length of arc of recess to the circular pitch

Answer: Option B

 

42. 

The bearing characteristic number is given by (where p = Bearing pressure on the projected bearing area, Z = Absolute viscosity of the lubricant, and N = Speed of the journal)

A.

B.

C.

D.

Answer: Option D

 

43. 

The cracks in helical springs used in railway carriages usually start on the inner side of the coil because of the fact that

A.

it is subjected to a higher stress than the outer side

B.

it is subjected to a higher cyclic loading than the outer side

C.

it is more stretched than the outer side during the manufacturing process

D.

it has a lower curvature than the outer side

Answer: Option B

 

44. 

In a marine flange coupling, the thickness of flange is taken as

A.

d/4

B.

d/3

C.

d/2

D.

3 d/4

Answer: Option B

 

45. 

The wire ropes make contact at

A.

bottom of groove of the pulley

B.

sides of groove of the pulley

C.

sides and bottom of groove of the pulley

D.

anywhere in the groove of the pulley

Answer: Option A

 

46. 

A metal pipe of 1 m diameter contains a fluid having a pressure of 1 N/mm2. If the permissible tensile stress in the metal is 20 N/mm2, then the thickness of the metal required for making the pipe will be

A.

5 mm

B.

10 mm

C.

15 mm

D.

25 mm

Answer: Option D

 

47. 

A tangent key is provided in pairs at right angles and each key is to withstand torsion in one direction only.

A.

Agree

B.

Disagree

Answer: Option A

 

48. 

When the speed of belt increases,

A.

the coefficient of friction between the belt and pulley increases

B.

the coefficient of friction between the belt and pulley decreases

C.

the power transmitted will decrease

D.

the power transmitted will increase

Answer: Option C

 

49. 

According to law of gearing, the common normal at the point of contact between a pair of teeth must always pass through the pitch point.

A.

Correct

B.

Incorrect

Answer: Option A

 

50. 

An involute pinion and gear are in mesh. If both have the same size of addendum, then there will be interference between the

A.

tip of the gear and flank of pinion

B.

tip of the pinion and flank of gear

C.

flanks of both gear and pinion

D.

tip of both gear and pinion

Answer: Option A