The length of the tube of a compound microscope is $10 \, cm$. The focal lengths of the objective and eye lenses are $0.5 \, cm$ and $1.0 \, cm$ respectively. The magnifying power of the microscope is about:

If the focal length of the objective and eye lens are $1.2 \, cm$ and $3 \, cm$ respectively,and the object is placed $1.25 \, cm$ away from the objective lens,and the final image is formed at infinity,the magnifying power of the microscope is:

Mention the maximum magnification of a simple microscope.

Magnifying power of a simple microscope is (when final image is formed at $D = 25 \ cm$ from eye)

The magnifying power of a microscope with an objective of $5\, mm$ focal length is $400$. The length of its tube is $20\, cm$. Then the focal length of the eye-piece is.....$cm$

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?......$mm$