Electric Current, Its Expression And units


Electric current

Rate of flow of charge through a given cross-section of a wire is called electric current. 
It is given by the formula, 


Steady current

An electric current that does not change with time is known as steady current. An example would be closing or opening a switch to add or remove a battery, current may initially change, but then reach a final ``steady-state'' value after a long time, or go to zero, depending on the situation.


Unit of current

The unit of current is or