The focal length of the objective lens of a compound microscope is

The least distance of distinct vision is $25 \ cm$. Find the magnifying power of a simple microscope of focal length $5 \ cm$ if the final image is formed at the least distance of distinct vision.

The objective and the eyepiece of a microscope have focal lengths of $4 \, mm$ and $25 \, mm$,respectively. The objective produces a real image $30$ times the size of the object. The final image is viewed at infinity. The near point of the microscope user is at $25 \, cm$. The overall magnification of the microscope is

Obtain the magnification for the image formed at infinity for a simple microscope.

The magnification power of a compound microscope is given in terms of the magnification of the objective $m_0$ and the magnification power of the eyepiece $m_E$. The total magnification is:

$A$ convex lens of focal length $12.5 \ cm$ is used as a simple microscope. When the image is formed at infinity,the magnification is . . . . . . . (Near point for normal vision is $25 \ cm$)