Electrical current - electrical theory

2.03 Electrical current (ii)

There is another equation which can be used to calculate the current flowing through a conductor. This can be used when we know the total amount of charge that has passed a point in the circuit over a known time period.

This equation clearly illustrates that current is the flow rate of electrical charge.

I = Q/t

I is the current measured in Amps (A)
Q is the total charge measured in Coulombs (C)
t is the time taken for the charge to flow past a point in a circuit. Time is measured in seconds (S)

Example
A charge of 100C passes a point in a circuit in 20 seconds
I = Q/t = 100/20 = 5 Amps