State the condition under which a large magnification can be achieved in an astronomical telescope.

Explanation

Magnifying power of an astronomical telescope is
`M = (-f_(0))/(f_(e))(1 + (f_(e))/(d))`
`:.` Two conditions for large magnification are ,
(i) focal length of objective lens `f_(0)` should be large
(ii) focal length of eye lens `f_(e)` should be small.