1. How can you bend light away from the normal?
2. How must light travel out of a substance if it is not going to be refracted?

A concave mirror and a convex lens are held separately in water. What changes, if any, do you expect in the focal length of either?

“A ray of light incident on a rectangular glass slab immersed in any medium emerges parallel to itself.” Draw labeled ray diagram to justify this statement.

Draw ray diagrams showing the image formation by a concave mirror when an object is placed:
Between pole and focus of the mirror.

How could you find the focal length of a convex lens rapidly but approximately?

What kind of lens can form:

1. An inverted magnified image?
2. An erect magnified image?
3. An inverted diminished image?
4. An erect diminished image?

State three characteristics of the image formed by a convex mirror.

With the help of a labelled diagram explain how a convex lens converges a beam of parallel light rays.

Refractive indices of four media A, B, C and D are given below:

Medium	Refractive index
A B C D	1.33 1.44 1.52 1.65

In which of these four media is the speed of light:

1. Maximum, and
2. Minimum?

Identify the device used as a spherical mirror or lens in following cases, when the image formed is virtual and erect in each case.Object is placed between infinity and device, image formed is diminished and between focus and optical centre on the same side as that of the object.