Question

A gaint refrecting telescope at an observatory has an objective lens of focal length `15 m`. If an eye piece lens of focal length `1 cm` is used, find the angular magnification of the telescope.
If this telescope is used to view the moon, what is the diameter of image of moon formed by objective lens ? The diameter of the moon is `3.42 xx 10^6 m` and radius of lunar orbit is `3.8 xx 10^8 m`.
A. `1000`
B. 1500
C. 2000
D. 3000

Answer 1

Correct Answer - B
Here, `f_(o) = 15 m = 15 xx 10^(2) cm, f_(e) = 1.0 cm`
`:.` magnification,`m = (f_(o))/(f_(e)) = (15 xx 10^(2))/(1) = 1500`