(a) The refractive index of water is 1.33 at a certain temperature. When the temperature of water is increased by 40°C, the refractive index changes to 'x'. State whether x < 1.33 or x > 1.33.

(b) State two differences between normal reflection and total internal reflection.

The below diagram shows that an observer sees the image of an object O at I.

(a) Name and define the phenomenon responsible for seeing the image at a different position.

(b) State the effect on X when:

1. Y increases
2. Y decreases

When sunlight passes through water droplets in the atmosphere it gets dispersed into its constituent colours forming a rainbow. A similar phenomenon is observed when white light passes through a prism.

(a) Which colour will show the maximum angle of deviation and which colour will show the minimum angle of deviation?

(b) If instead of sunlight, a green-coloured ray is passed through a glass prism. What will be the colour of the emergent ray?

(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 wavelength longer than the wavelength of these radiations.