The magnification produced by the objective lens and the eye lens of a compound microscope are $25$ and $6$ respectively. The magnifying power of this microscope is

Given below are two statements: one is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A$: For a simple microscope,the angular size of the object equals the angular size of the image.
Reason $R$: Magnification is achieved as the small object can be kept much closer to the eye than $25\, cm$ and hence it subtends a large angle.
In the light of the above statements,choose the most appropriate answer from the options given below:

What is a compound microscope? Explain its construction with the help of a figure.

Mention the maximum magnification of a simple microscope.

$A$ compound microscope has an objective of focal length $1.25 \ cm$ and an eyepiece of focal length $5 \ cm$ separated by a distance of $7.5 \ cm$. The total magnification produced by the microscope when the final image forms at infinity is

The image formed by an objective lens of a compound microscope is