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

$A$ 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....$cm$

If the focal lengths of the objective and eyepiece of an astronomical telescope are $200 \, cm$ and $4 \, cm$ respectively,then the length of the telescope for normal adjustment is ......... $cm$.

Where is the largest telescope in India? What is the diameter of the objective in it?

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

$A$ planet is observed by an astronomical refracting telescope having an objective of focal length $16 \, m$ and an eye-piece of focal length $2 \, cm$. Which of the following statements is correct?