If critical angle for a material to air is 30º, then the refractive index of the material will be :

Foundation

Physics Foundation

refraction from lens

Question

1.0

1.5

2.0

2.5

College PredictorLive

Know your College Admission Chances Based on your Rank/Percentile, Category and Home State.

Get your JEE Main Personalised Report with Top Predicted Colleges in JoSA

The critical angle (θ_c) is related to the refractive index (n) by Snell's law. For light passing from a material to air (n_air ≈ 1), the formula is:

$n = \frac{1}{\sin θ_{c}}$

Given θ_c = 30°, sin(30°) = 0.5. Therefore, n = 1 / 0.5 = 2.0.

Final Answer: 2.0