Where is the largest telescope in India? What is the diameter of the objective in it?

$A$ telescope has an eyepiece of focal length $5\, cm$ and an objective lens of focal length $60\, cm$. It is focused on a distant object such that the rays emerge from the eyepiece as parallel rays. Find the angular width of the image in degrees $(^o)$ if the object subtends an angle of $2^o$ at the objective.

The magnifying power of a refracting type of astronomical telescope is $m$. If the focal length of the eyepiece is doubled,then the magnifying power will become:

An astronomical refracting telescope has an objective of focal length $20 \, m$ and an eyepiece of focal length $2 \, cm$. Then:

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

Two convex lenses of focal lengths $0.3 \, m$ and $0.05 \, m$ are used to make a telescope. The distance kept between the two is .... $m$