# What Is Current?

Let’s start with charge.  Charge is measured in coulombs, 1 coulomb has $6.24 x 10^{18}$ electrons.

Charge of 1 electron:  Qe = $-1.6 x 10^{-19}$ coulomb.

Charge is carried by negative electrons and/or positive protons.  In a solid, the current is carried by electrons.

Current: is the rate of charge flow.

Current (I) = $\frac{Charge}{Time}$ OR I =$\frac{Q}{T}$

1 Ampere = $\frac{1 coulomb}{1 second}$

1 A = $\frac{1C}{1 S}$

Amp = $\frac{C}{ S}$