The correct option is (b) 180°

Best explanation: Given : α = 98°

Let θ = Angle turned through by the driving shaft.

We know that velocity ratio,

ω1/ω = cosα/1 – cos^2θsin^2α

The velocity ratio will be maximum when cos^2 θ is minimum, i.e. when

cos^2 θ = 1 or when θ = 0° or 180°.