4

0.25

0.5

1

2

D. 2

4

# Which is the false statement about the properties of instantaneous centre?

At the instantaneous center of rotation, one rigid link rotates instantaneously relative to another for the configuration of mechanism considered

The two rigid links have no linear velocities relative to each other at the instantaneous centre

The two rigid links which have no linear velocity relative to each other at this center have the same linear velocity to the third rigid link

The double centre can be denoted either by O2 or O12, but proper selection should be made

4

# The relation between number of links (l) and number of joints (j) in a kinematic chain is

l = (1/2).(j + 2)

l = (2/3).(j + 2)

l = (3/4).(j + 3)

l = j + 4

4

# The maximum efficiency of spiral gears is (where θ = Shaft angle, and φ = Friction angle)

sin (θ + φ) + 1/ cos (θ - φ) + 1

cos (θ - φ) + 1/ sin (θ + φ) + 1

cos (θ + φ) + 1/ cos (θ - φ) + 1

cos (θ - φ) + 1/ cos (θ + φ) + 1

4

# The Klein's method of construction for reciprocating engine mechanism

Is a simplified version of instantaneous centre method

Utilises a quadrilateral similar to the diagram of mechanism for reciprocating engine

Enables determination of coriolis component

Is based on the acceleration diagram

4

# The direction of linear velocity of any point on a link with respect to another point on the same link is

Parallel to the link joining the points

Perpendicular to the link joining the points

At 45° to the link joining the points

None of the above

4

Tractive force

Swaying couple

Hammer blow

None of these

4

# Creep in belt drive is due to

Weak material of the belt

Weak material of the pulley

Uneven extensions and contractions of the belt when it passes from tight side to slack side

Expansion of the belt

4

Sliding pair

Rolling pair

Surface pair

Higher pair

4

r sinφ

r cosφ

r tanφ

(r/2) cosφ

4

Greater than

Less than

Equal to

None of these

4

# Longitudinal vibrations are said to occur when the particles of a body moves

Perpendicular to its axis

Parallel to its axis

In a circle about its axis

None of these

4

# The frictional torque transmitted in a flat collar bearing, considering uniform wear, is (where r₁ and r₂ = External and internal radii of collar respectively)

(1/2) μ W (r₁ + r₂)

(2/3) μ W (r₁ + r₂)

(1/2) μ W [(r₁³ - r₂³)/(r₁² - r₂²)]

(2/3) μ W [(r₁³ - r₂³)/(r₁² - r₂²)]

4

# The tractive force in a locomotive with two cylinders is given by (where c = Fraction of reciprocating parts per cylinder, m = Mass of reciprocating parts, ω = Angular speed of crank, r = Radius of crank, and θ = Angle of inclination of crank to the line of stroke)

m.ω².r cosθ

c.m.ω².r sinθ

(1 - c).m.ω².r (cosθ - sinθ)

m.ω².r (cosθ - sinθ)

4

# A Hartnell governor is a

Pendulum type governor

Inertia governor

4

(1/2).Iω²

Iω²

(1/2). I ω ωP

I ω ωP

4

4

tp /16

tp /4

4 tp

16 tp

4

# The relative velocity of B with respect to A in a rigid link AB is

Parallel to AB

Perpendicular to AB

Along AB

At 45° to AB

4

θ/2

θ

4

# Which of the following is an inversion of a double slider crank chain?

Oldham's coupling

Elliptical trammel

Scotch yoke mechanism

All of these

4

# The indicator using Watt mechanism is known as

Thompson indicator

Richard indicator

Simplex indicator

Thomson indicator

4

# When the sleeve of a Porter governor moves downwards, the governor speed

Increases

Decreases

Remain unaffected

First increases and then decreases

4

# A governor is said to be stable, if the

Radius of rotation of balls increases as the equilibrium speed decreases

Radius of rotation of balls decreases as the equilibrium speed decreases

Radius of rotation of balls increases as the equilibrium speed increases

Radius of rotation of balls decreases as the equilibrium speed increases

4

# Two pulleys of radii r₁ and r₂ and at distance x apart are connected by means of an open belt drive. The length of the belt is

π (r₁ + r₂) + (r₁ + r₂)²/x + 2x

π (r₁ + r₂) + (r₁ - r₂)²/x + 2x

π (r₁ - r₂) + (r₁ - r₂)²/x + 2x

π (r₁ - r₂) + (r₁ + r₂)²/x + 2x

4

4

# A rotor supported at A and B carries two masses as shown in the below figure. The rotor is

Dynamically balanced

Statically balanced

Statically and dynamically balanced

Not balanced

4

Cylindrical pair

Turning pair

Rolling pair

Sliding pair

4

# Which of the following is an open pair?

Journal bearing

Ball and Socket joint

Leave screw and nut

None of the above

4

1/2π × √(s/m)

1/2π × √(g/δ)

0.4985/√δ

Any one of these