The refractive indexes of four substances P, Q, R and S are 1.57, 1.54, 2.52 and 1.33 respectively. When light travelling in air is incident on these substances at equal angles, the angle of refraction will be the maximum in:

The refractive indices of four media A, B, C and Dare 1.44, 1.52, 1.65 and 1.36 respectively. When light travelling in air is incident in these media at equal angles, the angle of refraction will be the minimum:

The speed of light in substance X is 1.25 x 10⁸ m/s and that in air is 3 x 10⁸ m/s. The refractive index of this substance will be:

The refractive index of water is:

The refractive index of water with respect to air is 4/3. The refractive index of air with respect to water will be: