Electrical Circuits and Current
Ever wondered why your phone stops working when the battery dies? It's all about electrical circuits and how current flows through them.
For electricity to flow, you need a closed circuit with a source of potential difference (like a battery). Think of current as the flow of electrical charge, measured in amperes (amps) using an ammeter connected in series. When 1 coulomb of charge passes a point in 1 second, you've got a current of 1 amp.
Current is conserved in circuits - this means the same amount flows around a complete loop. The potential difference (measured by a voltmeter in parallel) is what pushes the current around the circuit. The bigger the potential difference across a component, the bigger the current that flows through it.
Resistance makes it harder for current to flow through a circuit. You can control this using a variable resistor, and remember Ohm's Law: V = IR (voltage equals current times resistance).
Key Tip: Always remember that ammeters go in series (in the path of current) while voltmeters go in parallel (across components).
