Electrical Charge and Current

ELECTRICAL CHARGE (Q)

A circuit works when CHARGE is allowed to FLOW through it.

Usually these charges are free moving ELECTRONS or IONS.

Units: COULOMBS (C)

ELECTRIC CURRENT (I)

ELECTRIC CURRENT is the FLOW of electric CHARGE, quantified by the amount of charge passing a point in the circuit over time.

One of the key characteristics of current in a single closed loop is that it has the SAME VALUE at any point in the loop.

Units: AMPERES (A)

Current always flow AWAY from the POSITIVE side of the cell (the LONGER line)

The relationship between charge flow, current, and time is expressed by the equation:

Where:

• Charge flow (Q) is in Coulombs (C).
• Current (I) is in Amperes (A); "Amp" is also acceptable.
• Time (t) is in Seconds (s).