A telescope has an angular magnification of 250 when used with a 20 mm eyepiece. What is the focal length of the objective lens?
A) 2.5 m
B) 5.0 cm
C) 5.0 m
D) 5000 cm
E) 25 m

Question

Quizplus · Accepted Answer

The angular magnification (M) is given by the formula M = F_o / F_e, where F_o is the focal length of the objective lens and F_e is the focal length of the eyepiece. Given M = 250 and F_e = 20 mm (0.02 m), we can solve for F_o: F_o = M * F_e = 250 * 0.02 m = 5.0 m.

A Telescope Has an Angular Magnification of 250 When Used