Question

Electron microscope is based on principle of
a. Electromagnetic theory
b. Resolution of glass lenses
c. Magnification of glass lenses
d. Refraction of light

Answer 1

Hint: Microscopes are available in various sizes and particular usage. The most usual types of microscopes are the light microscope and electron microscope. Each of these microscopes has different features and is appropriate for different purposes. Radiation is used in both light microscopes and electron microscopes used to form detailed images of the samples, which cannot be produced with the help of the human eye.

Complete answer:
An electron microscope utilizes an ‘electron beam’ to form the image of the object and magnification is acquired by ‘electromagnetic fields’. For light or optical microscopes, in which ‘light waves’ are used to form the image and magnification is acquired by a system of ‘optical lenses’.

> Electromagnetic theory - The electron microscope utilizes electrostatic and electromagnetic lenses to control the electron beam and focus it on producing an image. These electron optical lenses are comparable to the glass lenses of a light optical microscope. So this is the correct option.

> Resolution of glass lenses - This principle is used on the light microscope. So it is the wrong option.

> Magnification of glass lenses - It is also used on the light microscope. So it is also the wrong option.

> Refraction of light - Refraction occurs when light travels through an area of space, thus it is the wrong option.

Hence, the correct answer is option (A).

Additional information:
Electromagnetic Theory is based on the basic principles of electromagnetism. These are experimental basis, electrostatics, magnetic fields of steady currents, etc. It uses electron beams as an illuminating source. This theory is an essential basis for understanding the devices, methods, and systems used for electrical energy.

Note: Some important points to be remembered are:
The electron microscopes have higher magnification.
The image formation depends upon the electron scattering.
The image is received on a zinc sulfate fluorescent screen.