The diagrams show the appearance of a fork when placed in front of and close to two mirrors A and B, turn by turn.

1. Which mirror is convex.
2. Which mirror is concave.

Give reasons for your choice.

A boy with a mouth 5cm wide stands 2m away from a plane mirror. Where is his image and how wide is the image of his mouth?

The image formed by a concave mirror is observed to be virtual, erect and larger than the object. Where should the position of the object be relative to the mirror? Draw ray diagram to justify your answer.

Why do we prefer a convex mirror as a rear-view mirror in vehicles?

Explain why, a real image can be projected on a screen but a virtual image cannot.

Draw ray diagrams showing the image formation by a convex lens when an object is placed:
At infinity.

Draw and complete the following diagrams to show what happens to the beams of light as they enter the glass block and then leave it:

Write the word AMBULANCE as it would appear when reflected in a plane mirror. Why is it sometimes written in this way (as its mirror image) on the front of an ambulance?

State and define the S.I. unit of power of a lens.