currant and circuit symbols

current is the flow of electrical charge

• electric current is a flow of electrical charge. electrical charge will only flow round a complete (closed) circuit if there is a potential difference, so a current can only flow if there's a source of potential difference. the unit of current is the ampere (A)
• in a single, closed loop, the current has the same value everywhere in the circuit
• potential difference (or voltage) is the driving force that pushes the charge around…