A ray of light passes from a medium A having refractive index 1.6 to the medium B having refractive index 1.5. The value of critical angle of medium A is……..

Options

(a) sin⁻¹ √16/15
(b) sin⁻¹(16/15)
(c) sin⁻¹(1/2)
(d) sin⁻¹(15/16)

Correct Answer:

sin⁻¹(15/16)

Explanation:

As the law of refraction, we have

sin i(c) / sin 90° = 1.5 / 1.6

Therefore sin i(c) = 15 / 16

where i(c) = critical angle of medium, A = sin⁻¹ (15 / 16)