4

4

6

8

10

A. 4

4

# The effective stress in wire ropes during normal working is equal to the stress due to

Axial load plus stress due to bending

Acceleration/retardation of masses plus stress due to bending

Axial load plus stress due to acceleration/retardation

Bending plus stress due to acceleration/retardation

4

124 d

138 d

151 d

168 d

4

Low

High

Moderate

None of these

4

# According to I.B.R., shearing resistance required to shear off the rivet per pitch length (in double shear) is (where n = Number of rivets per pitch length)

(π/4) d² × τ × n

1.875 × (π/4) d² × τ × n

2 × (π/4) d² × τ × n

3 × (π/4) d² × τ × n

4

Woodruff key

Feather key

4

40°

45°

38°

60°

4

# For unequal width of butt straps, the thicknesses of butt straps are

0.75 t for narrow strap on the inside and 0.625 t for wide strap on the outside

0.75 t for wide strap on the inside and 0.625 t for narrow strap on the outside

0.75 t for both the straps on the inside and outside

0.625 t for both the straps on the inside and outside

4

Bending stress

Shear stress

Tensile stress

Bearing stress

4

# The valve rod in a steam engine is connected to an eccentric rod by

Cotter joint

Bolted joint

Knuckle joint

Universal coupling

4

# A triple riveted butt joint with double straps of unequal width is to be designed for a boiler shell. The pitch of the rivets in the outer row is double the pitch in the inner row and zigzag riveting is proposed. Which of the following statement is correct?

There are four rivets per pitch length, all in double shear

There are four rivets per pitch length, out of which two are in single shear and two are in double shear

There are five rivets per pitch length, all in double shear

There are five rivets per pitch length, out of which four are in double shear and one is in single shear

4

# The temperature at which the new grains are formed in the metal is known as

Lower critical temperature

Upper critical temperature

Recrystallisation temperature

None of these

4

# The plasticity is the property of a material which enables it to

Regain its original shape after deformation when the external forces are removed

Draw into wires by the application of a tensile force

Resist fracture due to high impact loads

Retain deformation produced under load permanently

4

40°

122°

136°

152°

4

# The application of third type levers is found in

A pair of tongs

Hand wheel of a punching press

Lever of a loaded safety valve

Handle of a hand pump

4

T/2

T

2T

4T

4

0.70

0.25

0.40

0.55

4

# Rankine's theory is used for

Brittle materials

Ductile materials

Elastic materials

Plastic materials

4

# In order to determine the stresses in a thin cylinder due to an internal pressure, it is assumed that

The effect of curvature of the cylinder wall is neglected

The tensile stresses are uniformly distributed over the section of the walls

The effect of the restraining action of the heads at the end of the pressure vessel is neglected

All of the above

4

Tension

Shear

Compression

All of the above

4

# A compound cylinder with inner radius 50 mm and outer radius 70 mm is made by shrinking one cylinder on to the other cylinder, the junction radius is 60 mm and the junction pressure is 1.1 N/mm². The maximum hoop stress developed in the inner cylinder is

3.6 N/mm² compression

3.6 N/mm² tension

7.2 N/mm² compression

7.2 N/mm² tension

4

# Castle nut is a locking device in which

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

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

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

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

4

# Which is positive drive?

Flat belt drive

V-belt drive

Crossed belt drive

Timing belt

4

# Jam nut is a locking device in which

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

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

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

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

4

More

Less

Same

None of these

4

Bolt

Tap bolt

Stud

None of these

4

# Cold working

Increases the fatigue strength

Decreases the fatigue strength

Has no influence on fatigue strength

Alone has no influence on fatigue strength

4

# A coupling used to connect two perfectly aligned shafts, is

Muff coupling

Compression coupling

Flange coupling

All of these

4

Middle

Shank

4

45 to 60 %

63 to 70 %

70 to 83 %

80 to 90 %