The focal length of the objective of an astronomical telescope is $1.5 \ m$. Under normal adjustment,the length of the telescope is $1.56 \ m$. The focal length of the eyepiece is: (in $m$)

When a telescope is adjusted for parallel light,the distance of the objective from the eyepiece is found to be $80 \,cm$. The magnifying power of the telescope is $19$. The focal lengths of the lenses are

The magnifying power of an astronomical telescope is $8$. If the distance between the two lenses is $54 \, cm$,find the focal lengths of the eyepiece and the objective lens.

$A$ planet is observed by an astronomical telescope having an objective lens of focal length $16 \, m$ and an eye-piece of focal length $2 \, cm$. Find the correct statement.

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

$A$ 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
$(a)$ the telescope is in normal adjustment (i.e.,when the final image is at infinity)?
$(b)$ the final image is formed at the least distance of distinct vision $(25 \; cm)$?