Question

A telescope consists of an objective of focal length 150 cm and an eyepiece of focal length 6·0 cm. If the final image is formed at infinity, then calculate : (I) the length of the tube in this adjustment, and (II) the magnification produced.

Draw a labelled ray diagram showing the formation of the image at least distance of distinct vision by a compound microscope.

A small object is placed at a distance of 3·0 cm from a magnifier of focal length 4·0 cm. Find : (I) the position of the image formed, and (II) the linear magnification produced.

A card sheet divided into squares each of size 1 mm² is being viewed at a distance of 9 cm through a magnifying glass (a converging lens of focal length 9 cm) held close to the eye.