Question

A thin hollow prism of refracting angle 3°, filled with water gives a deviation of 1°. The refractive index of water is ______.

Options

• 1.59

• 1.33

• 1.46

• 1.51

Answer 1

A thin hollow prism of refracting angle 3°, filled with water gives a deviation of 1°. The refractive index of water is `underline("R"/3)`.

Explanation:

Angle of deviation of the light ray produced by prism is,

δ = A(μ - 1)   ....(i)

where, δ = angle of deviation

A = angle of prims and

μ = refractive index of the prism

Given, A = 3°, δ = 1° and µ = ?

Substituting the given values in Eq. (i), we get

1° = 3°(µ - 1) ⇒ µ = `4/3` = 1.33

Hence, the refractive index of the prism is 1.33.