If $F_o$ and $F_e$ are the focal lengths of the objective and eyepiece respectively of a telescope,then its magnifying power will be

$A$ telescope has an objective of focal length $50 \text{ cm}$ and an eyepiece of focal length $5 \text{ cm}$. The least distance of distinct vision is $25 \text{ cm}$. The telescope is focused for distinct vision on a scale $200 \text{ cm}$ away. The separation between the objective and the eyepiece is.......$\text{cm}$.

The length of an astronomical telescope for normal vision (relaxed eye) ($f_o$ = focal length of objective lens and $f_e$ = focal length of eye lens) is

If the tube length of an astronomical telescope is $105 \, cm$ and the magnifying power is $20$ for normal setting,calculate the focal length of the objective in $cm$.

The number of lenses in a terrestrial telescope is

$A$ Galileo telescope has an objective of focal length $100\,cm$ and magnifying power $50$. The distance between the two lenses in normal adjustment will be......$cm$