## Theory of Machine Oldham's coupling is the

Third inversion of double slider crank chain
Second inversion of single slider crank chain
Third inversion of slider crank chain
Second inversion of double slider crank chain

## Theory of Machine A rotor which is balanced statically but not dynamically is supported on two bearings L apart and at high speed of the rotor, reaction on the left bearing is R. The right side of the bearing is shifted to a new position 2L apart from the left bearing. At the same rotor speed, dynamic reaction on the left bearing in the new arrangement will

Become equal to R/4
Remain same as before
Become equal to R/2
Become equal to 2R

None of these
Above
At
Below

90° and 180°
45° and 225°
180° and 270°
270° and 360°

## Theory of Machine When the two elements of a pair have a surface contact when relative motion takes place and the surface of one element slides over the surface of the other, the pair formed is known as a

Higher pair
Lower pair
Self-closed pair
Force-closed pair

(ω × AB)²
ω × (AB)²
ω² × AB
ω × AB