Question

A large rectangular glass slab has two sets of parallel faces. Light ray is incident on the glass slab and trace of light ray is drawn. Now glass slab is rotated by ${90}^o$ such that light ray now passes to second set of parallel faces. What will be the effect on trace of light?

• A. Angle of deviation will change
• B. Lateral displacement will change
• C. No effect
• D. Depends on material of glass

Answer 1

The correct option is B Lateral displacement will change

Since glass slab is rectangular, $l\ne b$

When glass is rotated by ${90}^o$, thickness changes and hence lateral shift changes.