To understand electric current suppose there are two charged bodies having different potentials. Both the bodies are supported by an insulating stand. When these two charged bodies at different potential are connected by a metal wire, it is found that there is a flow of charge from the body at higher potential to another body at a lower potential. This flow of charge continues till their electric potential becomes equal.
This flow of electric charges in a conductor such as a metal wire is called electric current. The amount of electric charge passing through a given point of the conductor in one second gives the magnitude of electric current.
Current = 
I = 
or
Q = I X t
Where,
I = magnitude of current
Q = amount of electric charge
t = time
Current is a scalar quantity. Its S.I. unit is ampere which is denoted by letter A.
1 Ampere
The electric current passing through a conductor is said to be one ampere when 1coulomb of electric charge flows through it in 1 second.
Ampere = 
The electric current passing through a conductor is measured by an instrument called ammeter. The ammeter is connected in series with the conductor in which the electric current is to be measured.
How to Get a Continuous Flow of Electric Current
We know that an electric current flows between two points due to the potential difference between them. Thus, the electric current will flow continuously as long as the potential difference is maintained between the two points. And the simplest way to maintain a potential difference between the two ends of a conductor is to connect the conductor between the terminal of a cell or a battery.
Test Your Understanding and Answer These Questions:
- What is definition of electric current?
- What is S.I. unit of electric current?
- What is definition of 1 ampere?