A ray of light travelling in a transparent medium falls on a surface separating the medium from air, at an angle of incidence of 45° . The ray undergoes total internal reflection. If, μ is refractive index of the medium w.r.t. air, select the possible values of μ from the following

Question

A ray of light travelling in a transparent medium falls on a surface separating the medium from air, at an angle of incidence of 45° . The ray undergoes total internal reflection. If, μ is refractive index of the medium w.r.t. air, select the possible values of μ from the following (A) 1.5 (B) 1.6 (C) 1.2 (D) 1.3

Tardigrade Admin · Accepted Answer

For total internal reflection, i > C Therefore, C < 45° As μ=(1/ sin C) ∴ μ > (4/ sin 45°) or, μ > √2 The possible values of μ are 1.5 and 1.6

Q. A ray of light travelling in a transparent medium falls on a surface separating the medium from air, at an angle of incidence of 45∘. The ray undergoes total internal reflection. If, μ is refractive index of the medium w.r.t. air, select the possible values of μ from the following

1.5

1.6

1.2

1.3

For total internal reflection, i>C Therefore, C<45∘ As μ=sinC1​ ∴μ>sin45∘4​ or, μ>2​ The possible values of μ are 1.5 and 1.6

For total internal reflection, $i > C$
Therefore, $C < 4 5^{\circ}$
As $μ = \frac{1}{s i n C}$
$∴ μ > \frac{4}{s i n 4 5 ^{\circ}}$
or, $μ > 2$
The possible values of $μ$ are $1.5$ and $1.6$