Question

A monochromatic point source of light 'O' is seen through a rectangular glass block ABCD. Paths of two rays, in and outside the block, are shown in the given figure.

How does the shift depend on the thickness (AD or BC) of the block?

• A. The shift increases with increase in the thickness of the glass block
• B. The shift decreases with increase in the thickness of the glass block
• C. The shift is not affected by increase in the thickness of the glass block
• D. The shift increases or decreases with increase in the thickness of the glass block depending on the wavelength of light

Answer 1

The correct option is A

The shift increases with increase in the thickness of the glass block

The shift increases with increase in the thickness of the glass block.

If thickness is BC the shift is OI and if thickness is BC the shift is OI'. Therefore, OI' > OI (from figure).