A particular reflecting telescope has an objective mirror with a focal length of 1.2 m and an eyepiece lens of focal length 6 mm.What is the magnifying power of this telescope?
A) 5×
B) 2000×
C) 20×
D) 200×

Question

Quizplus · Accepted Answer

The magnifying power of a telescope is given by the ratio of the focal length of the objective lens (or mirror, in the case of a reflecting telescope) to the focal length of the eyepiece. Thus, magnifying power = focal length of objective / focal length of eyepiece = 1.2 m / 6 mm = 1200 mm / 6 mm = 200×.

A Particular Reflecting Telescope Has an Objective Mirror with a Focal