For which of the following colours will the magnifying power of a microscope be maximum?

Maximum magnification produced by a simple microscope of focal length $f=5 \,cm$ is

When the length of a microscope tube increases,its magnifying power

The length of the compound microscope is $14 \, cm$. The magnifying power for a relaxed eye is $25$. If the focal length of the eye lens is $5 \, cm$,then the object distance for the objective lens will be.......$ 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?......$mm$

If in a compound microscope, the objective has a focal length of $1.0 \text{ cm}$, the eyepiece has a focal length of $2.0 \text{ cm}$, the tube length is $20 \text{ cm}$, and the near point for an observer is $25 \text{ cm}$, then the value of the magnification of the compound microscope will be . . . . . . .