Rheostats are variable resistances, that is, it is a variable barrier that hinders the passage of electrical current in its conductor. With this variation, it is possible to increase or decrease the intensity of the electrical current in this circuit, responsible for conducting electricity.
There are two types of rheostats. Rheostats with continuously variable resistance and discontinuously variable resistance rheostats.
The continuously variable resistance rheostat is a relationship between the resistance of the conductor and its length.
The rheostat is made of coiled copper wire and over it there is the movement of a copper cursor, which is commanded by a button; besides being constituted by several resistances connected in series and a metallic rod.
When using the rheostat, the only precise information you have is that you only know how much resistance you can put on it.
Example of the use of rheostats in our daily lives - When increasing the volume of the sound, we are using a rheostat, this happens because as we increases the volume of the sound, automatically decreases the electrical resistance, all caused by the increase or decrease of the copper wire that makes up the rheostat.
We can conclude that the rheostat is a metallic wire that can be placed in the entire circuit or in just part of it.
Schematic representation of rheostats:
By Talita A. angels
Graduated in Physics
Brazil School Team
Electricity -Physics - Brazil School
Source: Brazil School - https://brasilescola.uol.com.br/fisica/o-que-um-reostato.htm