$A$ reflecting telescope utilizes

For an astronomical telescope,the focal length of the objective lens is $f_{0}$ and the eyepiece lens is $f_{e}$. Then the tube length of the telescope is . . . . . . .

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 .... $m$

The focal lengths of the lenses of an astronomical telescope are $50\, cm$ and $5\, cm$. The length of the telescope when the image is formed at the least distance of distinct vision is

If the tube length of an astronomical telescope is $96 \ cm$ and the magnifying power is $15$ for normal setting,then the focal length of the objective is . . . . . . $cm$.

$A$ reflecting telescope has a large mirror as its objective with a radius of curvature equal to $80 \, cm$. What is the magnifying power of this telescope if the eyepiece used has a focal length of $1.6 \, cm$?