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) At what distance should the lens be held from the card sheet in Exercise 9.22 in order to view the squares distinctly with the maximum possible magnifying power? (b) What is the magnification in this case? (c) Is the magnification equal to the magnifying power in this case? Explain.