Spark image
Resistance


The free electrons in a metal are in constant random motion. As they move about they collide with each other and with the atoms of the metal.

If a potential difference is now applied across the metal the electrons tend to move towards the positive connection. As they do so their progress is interrupted by collisions. These collisions impede their movement and this property of the material is called its resistance.
 
 
 
© Keith Gibbs 2009