Electrical Resistance

When the electrons flow through the conductor, they bump into the stationary atomic torsos of the conductor. The result is that the electrons are hindered in their movement. The electric resistance tells us how strong this hindrance of the electrical current is.
The symbol for the electrical resistance is R. Again, the symbol has a Latin origin. The word „resistere“ means to resist. The unit of the resistance is ohm (Ω). Ohm was the surname of the German physicist Georg Simon Ohm (1789-1854).
If you know the voltage and the amperage, you can calculate the electrical resistance. Our formula, which we always used to do that, in the following form is called Ohm's law:


This model helps you to understand what happens inside of the conductor. You can see how the electrons bump into the atomic torsos and how they are so hindered in their movement:

(the arrows of the electrons show the direction in which they move)