12,000 r.p.m.
9,360 r.p.m.
6,000 r.p.m.
5,367 r.p.m.

## Theory of Machine The magnitude of velocities of the points on a rigid link is

Directly proportional to the distance from the points to the instantaneous center and is perpendicular to the line joining the point to the instantaneous center
Inversely proportional to the distance from the points to the instantaneous center and is perpendicular to the line joining the point to the instantaneous center
Inversely proportional to the distance from the points to the instantaneous center and is parallel to the line joining the point to the instantaneous center
Directly proportional to the distance from the points to the instantaneous center and is parallel to the line joining the point to the instantaneous center

90°
180°
270°

## Theory of Machine Open pairs are those which have

Two elements that permit relative motion
Point or line contact between the two elements when in motion
Surface contact between the two elements when in motion
Elements of pairs not held together mechanically

## Theory of Machine Which of the following is an open pair?

Cam and follower
Journal bearing
Ball and socket joint
Lead screw and nut

Four
Five
Six
Seven