$A$ reflecting telescope utilizes

The number of lenses in a terrestrial telescope is

The magnifying power of a telescope with tube length $60 \; cm$ is $5$. What is the focal length of its eyepiece in $cm$?

Four lenses of focal length $\pm 15\; cm$ and $\pm 150 \;cm$ are available for making a telescope. To produce the largest magnification,the focal length (in $cm$) of the eyepiece should be

An astronomical telescope has an angular magnification of magnitude $5$ for distant objects. The separation between the objective and eyepiece is $36 \, cm$ and the final image is formed at infinity. The focal lengths of the objective and eyepiece are respectively:

The focal lengths of the objective lens and the eye lens of a Galilean telescope are $30\, cm$ and $3.0\, cm$ respectively. The telescope produces a virtual,erect image of an object situated far away from it at the least distance of distinct vision from the eye lens. In this condition,the magnifying power of the Galilean telescope should be: