Main menu Show/Hide Menu Introduction Summary Other Websites Electric current is the rate of flow of charge around a circuit. In this topic you need to know about the following: - The equation charge = current x time The equation potential difference = current x resistance Draw circuit diagrams and symbols correctly. What resistance is and how this affects current. What lamps, diodes, LDRs thermistors and resistors do. Use the arrows below to continue to revise. Summary Physics Menu