If in a compound microscope $m_1$ and $m_2$ are the linear magnifications of the objective lens and the eye lens respectively,then the magnifying power of the compound microscope will be:

In a compound microscope,the magnification will be large if the focal length of the eyepiece is:

In a compound microscope,the intermediate image is generally .......

$A$ student measures the thickness of a human hair by looking at it through a microscope of magnification $100$. He makes $20$ observations and finds that the average width of the hair in the field of view of the microscope is $3.5 \; mm$. What is the estimate on the thickness (in $mm$) of hair?

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

In a Ramsden eyepiece,two planoconvex lenses,each of focal length $f$,are separated by a distance of $12 \ cm$. The equivalent focal length (in $cm$) of the eyepiece is: