62. The Ackerman steering gear mechanism is preferred to the Davis steering gear mechanism, because

whole of the mechanism in the Ackerman steering gear is on the back of the front wheels
the Ackerman steering gear consists of turning pairs
the Ackerman steering gear is most economical
both (a) and (b)
✅ The correct answer is option D.

64. The sense of coriolis component 2 ωv is same as that of the relative velocity vector v rotated at

45° in the direction of rotation of the link containing the path
45° in the direction opposite to the rotation of the link containing the path
90° in the direction of rotation of the link containing the path
180° in the direction
✅ The correct answer is option C.

66. A body of weight W is required to move up the rough inclined plane whose angle of inclination with the horizontal is α. The effort applied parallel to the plane is given by (where μ = tan φ = Coefficient of friction between the plane and the body)

P = W tan α
P = W tan (α + φ)
P = W (sin α + μ cos α)
P = W (cos α + μ sin α
✅ The correct answer is option C.

68. In a steam engine, one method of obtaining the earlier cut-off with a simple slide valve is by increasing the angle of advance of the eccentric while the throw of the eccentric, steam lap and exhaust lap are kept constant. This method will

cause withdrawing or throttling of steam
reduce length of effective stroke of piston
reduce maximum opening of port to steam
all of these
✅ The correct answer is option B.