MHTCET 11 May 2024 Shift 2 Paper

Concept:For light going from a denser to a rarer medium, the critical angle depends inversely on the refractive index of the denser medium.Explanation:The critical angle is given by:$$\theta_c = \sin^{-1}\left(\frac{n_{\text{air}}}{n_{\text{glass}}}\right)$$Here, $n_{\text{air}}$ is constant.So, $\theta_c$ decreases when $n_{\text{glass}}$ increases.Due to dispersion, the refractive index of glass is higher for shorter wavelengths.Among the given colours, blue has the shortest wavelength, so it has the highest refractive index in glass.Hence, the critical angle is minimum for blue colour.Answer:Option D: blue colour.