Question

Two transparent media A and B are separated by a plane boundary. The speed of light in those media are 1.5 × 10⁸ m/s and 2.0 × 10⁸ m/ s, respectively. The critical angle for a ray of light for these two media is ______.

Options

• tan⁻¹ (0.750)

• sin⁻¹ (0.500)

• sin⁻¹ (0.750)

• tan⁻¹ (0.500)

Answer 1

The critical angle for a ray of light for these two media is sin⁻¹ (0.750).

Explanation:

_rn_b = `1/(sin θ_c) = "Speed of light in rarer medium"/"speed of light in denser medium"`

`1/(sin θ_c) = (2 xx 10^8)/(1.5 xx 10^8)`

`sin θ_c = 1.5/2`

sin θ_c = 0.75

θ_c = sin⁻¹ (0.75)