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

Difficult to manufacture
Wears rapidly
Both (A) and (B) above
Bulky

## Theory of Machine The frictional torque transmitted in a truncated conical pivot bearing, considering uniform wear, is

(2/3). μ W cosec α [(r₁³ - r₂³)/(r₁² - r₂²)]
(1/2). μ W cosec α (r₁ + r₂)
(1/2). μ W cosec α [(r₁³ - r₂³)/(r₁² - r₂²)]
(2/3).μ W cosec α (r₁ + r₂)

## Theory of Machine Cam angle is defined as the angle

Of rotation of the cam for a definite displacement of the follower
Moved by the cam from the instant the follower begins to rise, till it reaches its highest position
During which the follower returns to its initial position
Through which, the cam rotates during the period in which the follower remains in the highest position

## Theory of Machine A watt's governor can work satisfactorily at speeds from

80 to 100 r.p.m.
200 to 300 r.p.m.
100 to 200 r.p.m.
60 to 80 r.p.m.

## Theory of Machine In a four-bar chain it is required to give an oscillatory motion to the follower for a continuous rotation of the crank. For the lengths of 50 mm of crank and 70 mm of the follower, determine theoretical maximum length of coupler. The distance between fixed pivots of crank and followers is

Slightly more than 95 mm
45 mm
95 mm
Slightly less than 95 mm

Spur gear
Spiral gear
Bevel gear
Worm gear