Draw a neat labelled ray diagram to show the formation of an image by a magnifying glass. State three characteristics of the image.

Describe in brief how would you determine the approximate focal length of a convex lens.

The diagram in figure shows experimental setup for determination of the focal length of a lens using a plane mirror.

(i) Draw two rays from the point O of the object to show the formation of image I at O itself.

(ii) What is the size of the image I?

(iii) State two more characteristics of the image I.

(iv) Name the distance of the object O from the optical centre of the lens.

(v) To what point will the rays return if the mirror is moved away from the lens by a distance equal to the focal length of the lens?

Describe how you would determine the focal length of a converging lens, using a plane mirror and one pin. Draw a ray diagram to illustrate your answer.