A point object O is placed at a distance of 41 cm from a convex lens of focal length `f = 20` cm on its principal axis. A glass slab of thickness 3 cm and refractive index `mu = 1.5` is placed between the lens and the object with its faces perpendicular to the principal axis of the lens. Image of the object is formed at point `I_(1)`. Now the glass slab is tilted by an angle of `theta = 1°` (as shown in the Figure) and the final image is formed at `I_(2)`. Calculate the distance between points `I_(1)` and `I_(2)`. Consider only paraxial rays for the lens and near normal incidence for the glass slab.

Answer

`(pi)/(180)cm`