Show the lateral displacement of the ray on the diagram.

Draw ray diagrams showing the image formation by a concave lens when an object is placed:
At the focus of the lens.

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

Draw diagram to represent the action of a concave mirror on a beam of parallel light rays. Mark on this diagram principal axis, focus F, centre of curvature C, pole P and focal length ƒ, of the concave mirror.

Where must the object be placed for the image formed by a converging lens to be:

1. Real, inverted and smaller than the object?
2. Real, inverted and same size as the object?
3. Real, inverted and larger than the object?
4. Virtual, upright and larger than the object?

The optician’s prescription for a spectacle lens is marked +0.5D. What is the:

1. Nature of spectacle lens?
2. Focal length of spectacle lens?

A lens is cut into two equal halves: Along the principal axis.
What will be the focallength of each half?

Name the type of mirrors used in the design of solar furnaces. Explain how high temperature is achieved by this device.

A student focuses the image of a well illuminated distant object on a screen using a convex lens. After that he gradually moves the object towards the lens and each time focuses its image on the screen by adjusting the lens.

1. In which direction-towards the screen or away from the screen, does he move the lens?
2. What happens to the size of the image-does it decrease or increase?
3. What happens to the image on the screen when he moves the object very close to the lens?