Question

A point object O is placed at a distance of 0.3 m from a convex lens (focal length 0.2 m) cut into two halves each of which is displaced by 0.0005 m as shown in the figure.

Find the spacing between the images so formed.

(a)  0.1 cm

(b)  0.5 cm

(c)  0.3 cm

(d)  1 cm

Answer 1

Correct option  0.3 cm

Explanation :

m (for upper half) = + v/u = 60cm/30 cm = 2

so image is at (upper tip) at = 2 0.05 cm

= 1 cm

i.e. cm principal axis of upper. Half 

So spacing ­ 0.1 cm + 0.1 cm + 0.1 cm

 = 0.3 cm,