3) 30] According to Snell's law light is refracted when passing from one medium (index of refraction n) into another with index n2. a) [10] Show two cases of how refracted wave fronts travel: in one case n1 > n2, while in the other case n2 > n1. Draw for both separate cases the interface of the regions, indicate where n, and n2 apply, an incident beam, and refracted beam, as well as the normal to the interface where the incident beam hits it. Show arrows on the beams for the direction of light travel, and mark the angles. b) [10] Explain in one-two sentences and using a sketch the meaning of total internal reflection and state an application. c) [10] What do we mean by dispersion of light? Explain the phenomenon, and state an application