Optical Instruments: Microscope

The expression for magnifying power of compound microscope is

The focal lengths of the objective and the eye piece of a compound microscope are $2.0 \mathrm{cm}$ and $3.0 \mathrm{cm},$ respectively. The distance between the objective and the eye piece is $15.0 \mathrm{cm}.$ The final image formed by the eye piece is at infinity. The two lenses are thin. The distance in $\mathrm{cm}$ of the object and the image produced by the objective, measured from the objective lens, are respectively

A convex lens $\mathrm{A}$ of focal length $20 \mathrm{cm}$ and a concave lens $\mathrm{B}$ of focal length $5 \mathrm{cm}$ are kept along the same axis with a distance $\mathrm{d}$ between them. If a parallel beam of light falling on $\mathrm{A}$ leaves $\mathrm{B}$ as a parallel beam, then $\mathrm{d}$ is equal to _________ $\mathrm{cm}$.

What is the relation between visual angle and apparent size.

Define visual angle. 

What is the relation between visual angle and Apparent size

What is the unit of visual angle.

What angle subtended is the minimal visual acuity

Total magnification of compound microscope is $20$ while magnification for eye piece is $5$. If final image is formed at near point which is taken $20 \mathrm{cm}$ then focal length of eye piece is

The focal length of magnifying glass is $25 \mathrm{cm}$ then magnifying power this instrument when image is formed at infinity is ( near point for normal eye$=\mathrm{D}=25 \mathrm{cm}$)

An object is at distance $30 \mathrm{cm}$ from compound microscope of focal length $5 \mathrm{cm}$ and $25 \mathrm{cm}$ for objective and eye piece respectively. Magnifying power of microscope when image is formed at near point is 

A star subtends an angle of $2°$ at eye when seen through the telescope. It subtends an angle of $40°$ at eye. The magnifying power of the telescope is?

An object is placed at a distance $u$ from a simple microscope of focal length $f$. The angular magnification obtained depends

An electron microscope is superior to an optical microscope in

Electron microscope is better than optical microscope because of:

It the focal length of objective lens is increased then magnifying power of :

In a compound microscope, the intermediate image is

In a compound microscope, the objective and eyepiece have focal length of $0.95 \mathrm{cm}$ and $5 \mathrm{cm}$, respectively and are kept at a distance of $20 \mathrm{cm}$. The final image produced by this compound microscope is at a distance of $25 \mathrm{cm}$ from eyepiece. The total magnification is

The focal length of the objective of a microscope is