$A$ 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....$cm$

The astronomical telescope consists of an objective lens and an eye-piece. The focal length of the objective is:

If the focal lengths of the objective and eyepiece of an astronomical telescope are $200 \, cm$ and $4 \, cm$ respectively,what will be the magnifying power for distant vision (normal adjustment)?

$A$ small telescope has an objective lens of focal length $140\, cm$ and an eyepiece of focal length $5.0\, cm$. What is the magnifying power of the telescope for viewing distant objects when the telescope is in normal adjustment?

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

In normal adjustment,for a refracting telescope,the distance between the objective and the eyepiece is $30\,cm$. The focal length of the objective,when the angular magnification of the telescope is $2$,will be $.....\,cm$.