It is desired to obtain an erect image of an object, using concave mirror of focal length of 12cm.
Where will the image of this object be, if it is placed 24cm in front of the mirror? Draw ray diagram for this situation also to justify your answer.
Show the positions of pole, principal focus and the centre of curvature in the above ray diagrams.

List some things that concave lens and convex mirror have in common.

An object is placed at a distance of 30cm in front of a convex mirror of focal length 15cm. Write four characteristics of the image formed by the mirror.

Which kind of mirrors are used in the headlights of a motorcar and why?

A doctor has prescribed a corrective lens of power, -1.5D. Find the focal length of the lens. Is the prescribed lens diverging or converging?

Draw ray diagrams showing the image formation by a concave mirror when an object is placed:A little beyond centre of curvature of the mirror.

The following table gives the refractive indices of a few media,

	1	2	3	4	5
Medium:	Water	Crown glass	Rock salt	Ruby	Diamond
Refractive index:	1.33	1.52	1.54	1.71	2.42

Use this table to give an example of:

1. A medium pair so that light speeds up when it goes from one of these medium to another.
2. A medium pair so that light slows down when it goes from one of these medium to another.

Define:

1. Principal focus of a concave mirror.
2. Focal length of a concave mirror.

The boy walks towards the mirror at a speed of 1m/ s. At what speed does his image approach him?

State two positions in which a concave mirror produces a magnified image of a given object. List two differences between the two images.