An astronomical telescope has a large aperture to

$A$ simple telescope, consisting of an objective of focal length $60\, cm$ and a single eye lens of focal length $5\, cm$, is focused on a distant object in such a way that parallel rays emerge from the eye lens. If the object subtends an angle of $2^o$ at the objective, the angular width of the image is........$^o$.

In which type of telescope,an extra pair of inverting lens is available?

The aperture of a telescope is made large,because

The large aperture of an astronomical telescope is used to:

$A$ planet is observed by an astronomical telescope having an objective lens of focal length $16 \, m$ and an eye-piece of focal length $2 \, cm$. Find the correct statement.