Current and Circuit Symbols
Ever wondered how electricity actually moves around a circuit? Current is simply the flow of electrical charge, and it needs a potential difference (voltage) from a power supply to give it that essential push around the circuit.
Think of resistance as the electrical equivalent of friction - it opposes current flow. The higher the resistance in a component, the less current can squeeze through it. This relationship is fundamental to understanding how circuits behave.
You'll encounter loads of different circuit symbols in your exams. The basics include cells and batteries (your power sources), switches (open or closed), and components like bulbs, resistors, and fuses. Don't forget the measuring instruments - ammeters measure current whilst voltmeters measure potential difference.
Quick Tip: Remember that current flows from positive to negative around the outside of a circuit - this conventional current direction is what you'll use in all your calculations and circuit diagrams.