Electric current is a physical phenomenon, the essence of which is charge transfer. The charge can only move together with the charge carriers, i.e. in order to generate an electric current, it is necessary to move the charge carriers in a directionless manner. In our course, we primarily study electric current in metals, where the moving charge carriers are electrons.
Circuit
A circuit is a necessary prerequisite for a steady electric current to occur. A circuit consists of a power source (battery, battery, generator), switch(es) (which can be used to turn the current on and off), consumer(s) of electricity, and wires.
Permanent current occurs under certain conditions.
- An electric current can occur when there are free charge carriers, electrons or ions. For example, there are free electrons in metals and ions in solutions, their movement carries the charge. Charge carriers are always present, but if they cannot move, no electric current is produced.
- To move the charge carriers, it is necessary to apply a force to them. Free charge carriers are set in motion by electric force . Power sources such as generators and batteries are used to generate and store the necessary electrical power.