**Electric Currents
**

Current in a circuit
is a measure of the flow of charge past a specific point in a
circuit.

where *D**Q* is the amount of charge that flows by the
point in a time *D**t.*
The unit of current is **Amperes** or
**amps (A)**.
One amp is equivalent to one Coulomb per second. Charge is a
conserved quantity: it cannot be created or destroyed.
Therefore the current that flows into a junction must equal the
current that flows out. For instance, if three wires are attached
at a point as shown below, the total current flowing into the junction is equal to
the total current flowing out:

*i*_{1} = i_{2} + i_{3}

*Examples** **Resistors
index*
*Lecture index*