Question

An optical instrument used for angular magnification has a 25 D objective and a 20 D eyepiece. The tube length is 25 cm when the eye is least strained.

(a) Whether it is a microscope or a telescope ? (b) What is the angular magnification produced ?

Answer 1

(b) Since the final image is formed at infinity, the image produced by the objective should lie on the focal plane of the eye piece.