A simple quick return mechanism is shown in the figure. The forward to return ratio of the quick return mechanism is 2 : 1. If the radius of the crank O₁ P is 125mm, then the distance 'd' (in mm) between the crank centre to lever pivot centre point should be

A planar mechanism has 8 links and 10 rotary joints. The number of degrees of freedom of the mechanism, using Gruebler's criterion, is

For a four bar linkage in Toggle position, the value of mechanical advantage is

The number of inversions for a slider crank mechanism is