Question

a girl was playing with a thin beam of light from a laser torch by directing it from different directions on a convex lens held vertically. She was surprised to see that in a particular the beam of light continues to move along the same direction after passing through the lens.state the reasons for her observation. Draw a diagram to support your answer​

Answer 1

Answer:

Step-by-step explanation:

A convex lens can be split into three parts, top and bottom parts are like prism and middle part is like a slab.

It is well known that light enters through a transparent slab will not be deviated but only gets lateral displacement.

This lateral displacement proportional to the optical path in the slab. Optical path will be very less in the considered slab part of the lens

and hence lateral displacement also negligible.

Hence light ray enters in the optical centre region of lens passes through the lens with negligible deviation