(iii) (a) Mixture of red+blue+green is passed through a convex lens as shown in the diagram below. State whether the ray passes through a single point or through different points on principle axis after refraction.
(b) Name the invisible radiations which can be obtained using quartz prism? State one use of these radiations.
(c) Name one radiations having wavelenght longer than the wavelength of these radiations.
