An astronomical refractive telescope has an objective of focal length `20 m` and an eyepiece of focal length `2 cm`.

Options

A. The length of the telescope tube is 20.2 m
B. The magnification is 1000
C. The image formed is inverted
D. An objective of a larger aperture will increase the brightness and reduce chromatic aberration of the image

Explanation

The length of the telescope tube uis `f_(0)+f_(e)=20+(0.02)=20.2m`
Asloc, `" " m=20//0.02=1000`
Also, the image formed in inverted.