4

White metal

Silicon bronze

Monel metal

Phosphor bronze

A. White metal

4

# A sliding bearing which can support steady loads without any relative motion between the journal and the bearing, is called

Hydrostatic lubricated bearing

Hydrodynamic lubricated bearing

Boundary lubricated bearing

Zero film bearing

4

# A type of brake commonly used in motor cars is a

Shoe brake

Band and block brake

Band brake

Internal expanding brake

4

Gd⁴/ 8D3n

Gd3/ 8D3n

Gd⁴/ 4D3n

Gd⁴/ 8D²n

4

# If the centre distance of the mating gears having involute teeth is varied within limits, the velocity ratio.

Increases

Decreases

Remains unchanged

None of these

4

# When a closely coiled helical spring is subjected to a couple about its axis, the stress induced in the wire material of the spring is

Bending stress only

A combination of torsional shear stress and bending

Direct shear stress only

A combination of bending stress and direct shear stress

4

# Which of the following statement is correct?

The distance from a point on one thread to the corresponding point on the next thread is called pitch

The distance which a screw thread advances axially in one rotation of the nut is called lead

All of the above

4

# The ratio of driving tensions for flat belts, neglecting centrifugal tension, is (where T₁, and T₂ = Tensions on the tight and slack sides of belt respectively, μ = Coefficient of friction, between the belt and pulley, and θ = Angle of contact)

T₁/T₂ = μθ

log (T₁/T₂) = μθ

T₁/T₂ =eμθ

T₁/T₂ = log μθ

4

Ductile materials

Brittle materials

Equally serious in both cases

Depends on other factors

4

# The velocity of sliding ________ the distance of the point of contact from the pitch point.

Is directly proportional to

Is inversely proportional to

Is equal to cos φ multiplied by

Does not depend upon

4

# Which of the following statement is correct, for two shafts connected in parallel?

Torque in each shaft is the same

Shear stress in each shaft is the same

Angle of twist of each shaft is the same

Torsional stiffness of each shaft is the same

4

Bolts

Keys

Cotters

Rivets

4

# The objective of idler pulley in belt drive is to

Decrease the tendency of belt to slip

Increase the power transmission capacity

Increase the wrap angle and belt tension

All the above objectives

4

# Which of the following statement is correct?

The stress concentration in static loading is more serious in ductile materials and less serious in brittle materials

The stress concentration in static loading is more serious in brittle materials and less serious in ductile materials

The toughness of a material increases when it is heated

The shear stress in a beam varies from zero at the neutral surface and maximum at the outer fibres

4

# The connecting rod bolts are tightened up with initial tension greater than the external load so that

Joint may not open up

Bolts are weakest elements

The resultant load on the bolt would not be affected by the external cyclic load

Bolts will not loosen during service

4

# A connecting rod subjected to an axial load may buckle with

X-axis as neutral axis

Y-axis as neutral axis

X-axis or Y-axis as neutral axis

Z-axis

4

# If the size of a standard specimen for a fatigue testing machine is increased, the endurance limit for the material will

Have same value as that of standard specimen

Increase

Decrease

None of these

4

# In order to obtain bolt of uniform strength

Increase shank diameter

Increase its length

Drill an axial hole through head up to threaded portion so that shank area is equal to root area of thread

Tighten die bolt properly

4

# A machine part subjected to __________ is called a strut.

An axial compressive force

A tangential force

An axial tensile force

Any one of these

4

# Which of the following statement is correct regarding power screws?

The efficiency of a self locking screw can not be more than 50%

The efficiency of Acme (trapezoidal) thread is less than that of a square thread

If the friction angle is less than the helix angle of the screw, then the efficiency will be more than 50%

(A) and (B) Only

4

# Which of the following formula is used in designing a connecting rod?

Euler's formula

Rankine's formula

Johnson's straight line formula

Johnson's parabolic formula

4

# Basic shaft is one

Whose upper deviation is zero

Whose lower deviation is zero

Whose lower as well as upper deviations are zero

Does not exist

4

Metric

Buttress

Acme

Square

4

# A bolt of M 24 × 2 means that

The pitch of the thread is 24 mm and depth is 2 mm

Cross-sectional area of the threads is 24 mm²

The nominal diameter of bolt is 24 mm and pitch is 2 mm

The effective diameter of bolt is 24 mm and there are 2 threads per cm

4

2.5

2.8

3.0

3.5

4

# Which of the following statement is wrong?

A key is used as a temporary fastening

A key is subjected to tensile stresses

A key is always inserted parallel to the axis of the shaft

A key prevents relative motion between the shaft and boss of the pulley

4

Working depth

Clearance

Backlash

Face width

4

12

14

18

24

4

½

1

2

4

4

Flanged

Bell and spigot

Expansion

4

1-3 m/s

3-15 m/s

15-30 m/s

30-50 m/s