The length of a telescope is 1.60 m and it has a magnification of 60.0. What is the focal length of the eyepiece?
A) 2.62 cm
B) 1.16 cm
C) 100 cm
D) 96.0 cm
E) 60.0 cm

Question

Quizplus · Accepted Answer

The magnification (M) of a telescope 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. The length of the telescope is approximately the sum of the focal lengths of the objective and the eyepiece, so L ≈ f_o + f_e. Given M = 60.0 and L = 1.60 m = 160 cm, we can rearrange the magnification formula to solve for f_e: f_e = f_o / M. Assuming the length of the telescope is mostly the focal length of the objective lens, f_o ≈ L, so f_e ≈ L / M = 160 cm / 60 = 2.67 cm, which is closest to choice A, 2.62 cm.

The Length of a Telescope Is 1