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(a) A ray of white light is incident on one face of a triangular glass prism.
(i) Draw a ray diagram to illustrate the dispersion of white light by the prism, showing only the red ® and violet (V) rays.
(ii) On the same diagram drawn in
(i), mark and label the initial angle of incidence, i, and the angles of reflection on the first face for red #r_R# and for violet #r_V#.
(iii) Snell’s law for the red and violet colours can be written as # n_R=sini/sinr_R# and #n_v=sini/sinr_v# respectively. Show that #n_v >n_R#.
(b) Calculate the critical angle for a material whose refractive index is 1.40.