Question

A roller is made by joining together two corners at their vertices O. It is kept on two rails AB and CD which are placed a symmetrically (see the figure), with its axis perpendicular to CD) and its centre O at the centre of line joining AB and CD (see the figure. It is given a light path, so that it starts rolling with its centre O moving parallel to CD in the direction shown. As it moves, the roller will tend to

(a) Turn left

(b) Turn right

(c) Go straight

(d) Turn left and right alternately

Answer 1

Correct Option (a) Turn left

Explanation: 

As, the wheel rolls forward the radius of  the wheel decreases along AB, hence for the same number of rotations it moves less distance along AB, hence it turns left.