Simple Microscope

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 simple microscope ?

If an astronomical telescope has objective and eye-pieces of focal length $200 \mathrm{cm}$ and $4 \mathrm{cm}$ respectively, then the magnifying power of the telescope for the normal vision is:

The astronomical telescope consist of objective and eyepiece. The focal length of the objective is

Tom's lenses of focal lengths $\pm 15 \mathrm{cm}$ and $\pm 150 \mathrm{cm}$ are available for making a telescope. To produce the largest magnification, the focal-length of the eyepiece should be-

The length of an astronomical telescope for normal vision will be 

An astronomical refractive telescope has an objective of focal length $20 \mathrm{m}$ and an eyepiece of focal length $2 \mathrm{cm}$, then-

An astronomical telescope, in normal adjustment position, has magnifying power $5$. The distance between the objective and the eye-piece is $120 \mathrm{cm}.$ Calculate the focal lengths of the objective and of the eye-piece.

A coin is placed at the bottom of a beaker containing water (refractive index $=\frac{4}{3}$) to a depth of $\text{12cm}$. By what height the coin appears to be raised when seen from vertically above?

An object is placed at a distance of $0.25 \mathrm{m}$ in front of a plane mirror. The distance between the object and the image is

A converging lens is used to form an image on a screen when the upper half of the lens is covered by an opaque screen-

In a concave mirror, when the object is at $\mathrm{C}$, the size of the image.

If an object is at infinity, what will be the position of an image formed due to convex lens?

An object gets closer to the focal point of a convex lens from infinity, its image

If the object is placed between infinity and optical centre $\mathrm{O}$ of the concave lens, how will the image be formed after refraction.

When an object is placed at a distance of $60cm$ From a convex mirror, the linear magnification produced is $\raisebox{1ex}{$1$}\!\left/ \!\raisebox{-1ex}{$2$}\right.$. Where should the object be placed to obtain a magnification of $\raisebox{1ex}{$1$}\!\left/ \!\raisebox{-1ex}{$3$}\right.$ ?

What is the position of the object for a simple microscope ? What is the maximum magnification of a simple microscope for a realistic focal length?

Discus about simple microscope and obtain the equation for magnification for near point focussing and normal focussing..

Discus about simple microscope and obtain an equation for magnification for near point focusing and normal focusing.

The formula for linear magnification in an optical instrument is: