152) The design of pin of a rocker arm of an I.C. engine is based on

153) For a shaft diameter of 100 mm, the number of bolts in a flange coupling should be

154) A wood-ruff key is

155) In a V-belt drive, the belt makes contact at the bottom of the groove of the pulley.

156) In worm gears, the pressure angle is half the angle between two inclined faces in axial plane.