Question

A ray of light when incident upon a thin prism suffers a minimum deviation of 39°. If the shaded half portion of the prism is removed, then the same ray will ______.

Options

• suffer a deviation of 19.5°

• suffer a deviation of 39° 

• not suffer any deviation 

• will be totally internally reflected

Answer 1

A ray of light when incident upon a thin prism suffers a minimum deviation of 39°. If the shaded half portion of the prism is removed, then the same ray will suffer a deviation of 19.5°.

Explanation:

δ = (μ - 1)A

δ ∝ A

∴ `delta_2/delta_1 = "A"_2/"A"_1`

∴ `delta_2/delta_1 = ("A"//2)/"A" = 1/2`

∴ `delta_2 = delta_1/2`

`delta_2 = 39/2`

= 19.5°