An object is placed at a distance of 12cm in front of a concave mirror of radius of curvature 30cm. List four characteristics of the image formed by the mirror.

Draw ray diagrams showing the image formation by a convex lens when an object is placed:At twice the focal length of the lens.

Explain with the help of a diagram, why a pencil partly immersed in water appears to be bent at the water surface.

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

Draw a diagram to represent a convex mirror. On this diagram mark principal axis, principal focus F and the centre of curvature C if the focal length of convex mirror is 3cm.

What is the position of image when an object is placed at a distance of 10cm from a convex lens of focal length 10cm?

How will you distinguish between a plane mirror, a concave mirror and a convex mirror without touching them?

Where would the image be formed by a convex mirror if the object is placed:

1. Between infinity and pole of the mirror?
2. At infinity?

Draw labelled ray-diagrams to show the formation of image in both the cases.

What is meant by power of a lens? What does its sign (+ve or -ve) indicate? State its S.I. unit. How is this unit related to focal length of a lens?

Which type of mirror is used in a solar furnace? Support your answer with reason.