The image formed by an objective lens of a compound microscope is

The magnification produced by the objective lens and the eye lens of a compound microscope are $25$ and $6$ respectively. The magnifying power of this microscope is

If the tube-length $(L)$ of a compound microscope increases, then its magnification . . . . . . .

$A$ compound microscope has a magnifying power of $30$. The focal length of its eyepiece is $5 \ cm$. Assuming the final image is at the least distance of distinct vision $(25 \ cm)$,the magnification produced by the objective is:

We wish to make a microscope with the help of two positive lenses,both with a focal length of $20\, mm$ each,and the object is positioned $25\, mm$ from the objective lens. How far apart should the lenses be so that the final image is formed at infinity?......$mm$

The focal lengths of the objective and eyepiece of a compound microscope are $1 \, cm$ and $5 \, cm$ respectively. If the magnification is $45$,what is the length of the tube in $cm$?