Answer:
θ_c = 36.87°
Explanation:
Index of refraction for index medium; n_i = 2
Index of refraction for Refractive medium; n_r = 1.2
Formula to find the critical angle is given;
n_i(sin θ_c) = n_r(sin 90)
Where θ_c is critical angle.
Thus;
2 × (sin θ_c) = 1.2 × 1
(sin θ_c) = 1.2/2
(sin θ_c) = 0.6
θ_c = sin^(-1) 0.6
θ_c = 36.87°
