The ratio of velocities of a light ray in the air to the given medium is a refractive index. Thus, the relation between the critical angle and refractive index can be established as the Critical angle is inversely proportional to the refractive index. Angle of deviation is directly proportional to the refractive index of the material of prism. For a given angle of incidence the prism with higher refractive index produces a greater deviation than the prism which has a lower refractive index. No, the refractive index for a given pair of media does not depend on the angle of incidence. The refractive index for a given pair of media is a constant because, according to Snell's law, the ratio of sine of angle of incidence to sine of angle of refraction is constant which is equal to the refractive index. When light enters a material with higher refractive index, the angle of refraction will be smaller than the angle of incidence and the light will be refracted towards the normal of the surface. The higher the refractive index, the closer to the normal direction the light will travel. It's totally independent of angle of incidence of light. Refraction through a prism δ=i+e- A. Factors on which angle of deviation depends: angle of incidence, the wavelength of light used, the material of the prism, the angle of prism. The relationship between refractive index and angle of minimum deviation is given by: μ=sinisinr or μ=sin A+m2sinA/2. The refractive index of the material used in the prism:n=sin(A+Dm2)sin(A2)Where Dm is the angle of minimum deviation and A is the prism angle. In regions of the spectrum where the material does not absorb light, the refractive index tends to decrease with increasing wavelength, and thus increase with frequency. This is called "normal dispersion", in contrast to "anomalous dispersion", where the refractive index increases with wavelength. The equation is not based upon any assumptions about the variation of n with the frequency/wavelength of the light. However the refractive index does change with frequency. This effect is called optical dispersion. The cause is the way the interaction of the light and the electrons in the medium change with frequency. The refractive index of a medium is dependent (to some extent) upon the frequency of light passing through, with the highest frequencies having the highest values of n. For example, in ordinary glass the refractive index for violet light is about one percent greater than that for red light.Therefore, the refractive index is stated to be inversely proportional to the wavelength. Refractive index is inversely proportional to the wavelength of light and refractive index is a measure of the bending of a light ray when it passes from one medium into another. It indicates the optical density of the transparent medium. The wavelength is measured in metres, the velocity is measured in metres per second, and the frequency is measured in hertz. Therefore, we can conclude that the wavelength is inversely proportional to the refractive index of the material in which the wave is travelling.