Question

A girl was playing with a thin beam of light from her laser torch by directing it from different directions on a convex lens held vertically. She was surprised to see that in a particular direction the beam of light continues to move along the same direction after passing through the lens. 

(i) State the reason for this observation.  

(ii) If white light source is used with (a) parallel, (b) non-parallel sides, record your observations

Answer 1

(i) Reason is lateral displacement. 

Lateral displacement depends upon the thickness of the slab, the incident and refraction angles.

(ii) (a) If the white light source is used with the parallel side the ray will pass through the focus.

(b) Light rays will not pass through the nonparallel side.