In a compound microscope,the focal length and aperture of the objective lens used are,respectively:

Fingerprints are observed by the use of

In which of the following is the final image erect?

An angular magnification (magnifying power) of $30X$ is desired using an objective of focal length $1.25 \, cm$ and an eyepiece of focal length $5 \, cm$. How will you set up the compound microscope?

$A$ man uses a thin convex lens of focal length $5 \, cm$ as a magnifying glass. He reads a book by holding it close to his near point of $25 \, cm$. What are the closest and farthest distances at which he can keep the book from the lens to read clearly?

The image formed by an objective of a compound microscope is