Which is meant by electric current? Name and define S.I unit. In a conductor, if electrons are flowing from B to A, what is the direction of conventional current? Give justification for your answer.

Electric Current
Definition: Electric current is the rate of flow of electric charge through a conductor or circuit. It is represented by the symbol II.
Formula:
I=QtI = \frac{Q}{t}
Where:
• II is the current (in amperes, A),
• QQ is the charge (in coulombs, C),
• tt is the time (in seconds, s).
S.I. Unit of Electric Current
The S.I. unit of electric current is the ampere (A).
Definition of 1 Ampere: A conductor carries a current of 1 ampere when a charge of 1 coulomb flows through it in 1 second.
1 A=1 C/s1 \, \text{A} = 1 \, \text{C}/\text{s}
Direction of Conventional Current
When electrons flow in a conductor from BB to AA, the conventional current flows in the opposite direction, i.e., from AA to BB.
Justification:
• Electrons are negatively charged particles. Their flow constitutes the actual flow of electric charge.
• By convention, electric current is defined as the flow of positive charges. Thus, the direction of conventional current is taken opposite to the actual flow of electrons.
Key Points
1. The concept of conventional current was established before the discovery of electrons.
2. In metallic conductors, the flow of electrons creates the current, but the convention assumes the flow of positive charges.