The Yerkes refracting telescope has a 1-m diameter objective lens of focal length 20 m and an eyepiece of focal length 3.1 cm.What is the magnification of the planet Mars as seen through this telescope?
A)160
B)320
C)650
D)1 000

Question

Quizplus · Accepted Answer

The magnification of a telescope is given by the ratio of the focal length of the objective lens to the focal length of the eyepiece. 
Magnification = Focal length of objective lens / Focal length of eyepiece
Substituting the given values, 
Magnification = 20m / 3.1cm = 20,000mm / 31mm = 645.16 ≈ 650
Therefore, the magnification of the planet Mars as seen through this telescope is approximately 650.

The Yerkes Refracting Telescope Has a 1-M Diameter Objective Lens