What is the primary purpose of the eyepiece in a telescope?

If the length of the tube of an astronomical telescope is $105 \, cm$ and its magnification power for normal adjustment is $20$,then the focal length of its objective lens will be ....... $cm$.

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:

The focal length of the objective lens of a telescope is $30 \text{ cm}$ and that of its eye lens is $3 \text{ cm}$. It is focused on a scale at a distance $2 \text{ m}$ from it. The distance of the objective lens from the eye lens to see the clear image is: (in $\text{ cm}$)

What is a telescope?

What is the angular magnification of a telescope if the focal lengths of the objective and eye lenses are $10 \ cm$ and $10 \ mm$ respectively,and the tube length is $11 \ cm$?