4

l - 2

l - 1

l

l + 1

C. l

4

Lower pair

Higher pair

Turning pair

Sliding pair

4

18

20

30

34

4

5,367 r.p.m.

6,000 r.p.m.

9,360 r.p.m.

12,000 r.p.m.

4

# The frictional torque transmitted in a flat collar bearing, considering uniform pressure, 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 train value of a gear train is

Equal to velocity ratio of a gear train

Reciprocal of velocity ratio of a gear train

Always greater than unity

Always less than unity

4

10° to 20°

20° to 30°

30° to 40°

60° to 80°

4

# The main disadvantage of the sliding pair is that it is

Bulky

Wears rapidly

Difficult to manufacture

Both (A) and (B) above

4

# In under damped vibrating system, the amplitude of vibration

Decreases linearly with time

Increases linearly with time

Decreases exponentially with time

Increases exponentially with time

4

# A body is said to be under forced vibrations, when

There is a reduction in amplitude after every cycle of vibration

No external force acts on a body, after giving it an initial displacement

A body vibrates under the influence of external force

None of the above

4

# When two links are connected by a pin joint, their instantaneous centre lies

On their point of contact

At the centre of curvature

At the centre of circle

At the pin joint

4

# The direction of Coriolis component of acceleration is the direction

Of relative velocity vector for the two coincident points rotated by 90° in the direction of the angular velocity of the rotation of the link

Along the centripetal acceleration

Along tangential acceleration

Along perpendicular to angular velocity

4

# In multi V-belt transmission, if one of the belt is broken, we have to change the

Broken belt

Broken belt and its adjacent belts

All the belts

There is no need of changing any one as remaining belts can take care of transmission of load

4

Halved

Doubled

None of these

4

D/T

T/D

2D/T

2T/D

4

# A friction circle is a circle drawn when a journal rotates in a bearing. Its radius depends upon the coefficient of friction and the

Magnitude of the forces on journal

Angular velocity of journal

Clearance between journal and bearing

4

# The centre of gravity of a coupler link in a four bar mechanism will experience

No acceleration

Only linear acceleration

Only angular acceleration

Both linear and angular acceleration

4

ω √(x² - r²)

ω √(r² - x²)

ω² √(x² - r²)

ω² √(r² - x²)

4

# Which of the following is a pendulum type governor?

Watt governor

Porter governor

Hartnell governor

None of these

4

# In the two rotor system as shown in the below figure (I₁ < I₂), a node of vibration is situated

Between I₁, and I₂ but nearer I₁

Between I₁, and I₂ but nearer to I₂

Exactly in the middle of the shaft

Nearer to I₁ but outside

4

Infinity

Zero

Any +ve value

Any -ve value

4

# For two governors A and B, the lift of sleeve of governor A is more than that of governor B, for a given fractional change in speed. It indicates that

Governor A is more sensitive than governor B

Governor B is more sensitive than governor A

Both governors A and B are equally sensitive

None of the above

4

Machine

Structure

Mechanism

Inversion

4

# A Porter governor is a

Pendulum type governor

Inertia governor

4

0.2

0.4

0.6

0.8

4

# The danger of breakage and vibration is maximum

Below the critical speed

Near the critical speed

Above the critical speed

None of these

4

0° and 90°

180° and 360°

Both (A) and (B)

None of these

4

# The size of a gear is usually specified by

Pressure angle

Circular pitch

Diametral pitch

Pitch circle diameter

4

# Kinematic pairs are those which have

Two elements held together mechanically

Two elements having relative motion

Two elements having Coriolis component

Minimum of two instantaneous centres

4

# Whitworth quick return mechanism is obtained by inversion of

Slider crank mechanism

Kinematic chain

Roller cam mechanism