The objective of an astronomical telescope has a focal length of 900 mm. The telescope has eyepieces of focal lengths 20 mm, 15 mm, and 10 mm. What is the largest magnification for this telescope?
A) 920
B) 900
C) 880
D) 90
E) 60

Question

Quizplus · Accepted Answer

The magnification of a telescope is given by the formula: Magnification = Focal length of objective / Focal length of eyepiece. Using the eyepiece with the shortest focal length (10 mm) gives the largest magnification: 900 mm / 10 mm = 90.

The Objective of an Astronomical Telescope Has a Focal Length