AIIMS 2018 Physics Total Internal Reflection MCQ Question

For total internal reflection to occur at the vertical face of a rectangular glass slab, the angle of incidence must exceed the critical angle, which is determined by the refractive index (n) of the glass relative to air (n₁ = 1). The critical angle (θ_c) can be calculated using Snell's Law: sin(θ_c) = n₁/n₂, where n₂ is the refractive index of the glass. For total internal reflection, this leads to the condition n > √3/2, making option A (√3/2) the minimum refractive index required.

Options B, C, and D provide values that do not meet the critical angle requirement for total internal reflection, as they suggest higher indices that would not allow for the necessary conditions to be satisfied.