Define and explain the term electric current. What is the difference between electronic current and conventional current?

Definition of Electric Current

Electric current ($I$) is defined as the rate of flow of electric charge through a conductor or circuit. Mathematically, it is expressed as:

I=Q/t​

where:

• $I$ = current (in amperes, A
• $Q$ = charge (in coulombs, C)
• $t$ = time (in seconds, s)

The SI unit of electric current is the ampere (A), where 1 ampere = 1 coulomb per second (1A=1C/s).

Types of Current Flow

There are two types of current flow based on charge carrier movement:

1. Conventional Current

• Defined as the flow of positive charges (or equivalent flow of positive charge) from the positive terminal to the negative terminal of a power source.
• Historically, scientists assumed that positive charges flow in a circuit, which led to this convention.
• Used in circuit diagrams and theoretical analysis.

2. Electronic Current

• In reality, current in conductors (like metals) is due to the movement of electrons.
• Electrons carry a negative charge and move from the negative terminal to the positive terminal of a power source.
• The direction of electron flow is opposite to conventional current.

Key Difference Between Electronic Current and Conventional Current

Conclusion

While conventional current is widely used in electrical engineering and circuit diagrams, the actual current in metallic conductors is due to electron flow, which moves in the opposite direction.