A small roller of diameter 20 cm has an axle of diameter 10 cm (see figure below on the left). It is on a horizontal floor and a meter scale is positioned horizontally on its axle with one edge of the scale on top of the axel (see figure on the right). The scale is now pushed slowly on the axle so that it moves without slipping on the axle, and the roller without slipping. After the roller has moved 50 cm, the position of the scale will look like (figures are schematic and not drawn to scale)

Options

A.
B.
C.
D.

Answer

B

Explanation

Angular displacement `theta=(S_(0))/(10)=5`

Displacement of point `B,S=r.theta=15xx5=75cm`
Displacement of roller `=50cm`
Relative displacement `=75-50=25cm`