4, 4
4, 5
4, 6
5, 4

## Theory of Machine When the addenda on pinion and wheel is such that the path of approach and path of recess are half of their maximum possible values, then the length of the path of contact is given by (where r = Pitch circle radius of pinion, R = Pitch circle radius of wheel, and φ = Pressure angle)

[(r + R) cosφ]/2
[(r² + R²) cosφ]/2
[(r² + R²) sinφ]/2
[(r + R) sinφ]/2

## Theory of Machine Which is the false statement about the properties of instantaneous center?

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

## Theory of Machine The example of completely constrained motion is a

Motion of a square bar in a square hole
Motion of a piston in the cylinder of a steam engine
Motion of a shaft with collars at each end in a circular hole
All of these

## Theory of Machine In a Hartnell governor, if a spring of greater stiffness is used, then the governor will be

Less sensitive
Unaffected of sensitivity
More sensitive
Isochronous

## Theory of Machine In a rigid link OA, velocity of 'A' w.r.t. 'O' will be

Parallel to OA
Along AO
At 45° to OA
Perpendicular to OA