Question

in which instrument following are essential?
1)Internal vacuum 2)use of electromagnet
3)use of beam of electrons​

Answer 1

Answer:

use of eleteromegnet is your answer.

Mark my answer as brillant

Answer 2

Answer:

Internal vacuum, use of electromagnet

and use of a beam of electrons​ is found in electron microscopes.

Explanation:

In the case of electron microscopes, the light source is replaced by a beam of electrons.

The specimen has to be prepared in a special way and kept inside a vacuum chamber as electrons cannot travel far in the air.

The lenses of the microscope are replaced by coil-shaped electromagnets through which the beam of electrons travel.