Simple Circuits & Components
📋 What it is
A circuit is a complete loop; current only flows when the loop is unbroken from + to − of a source.
🗣️ Coach says
A circuit is a loop for charge to travel. You need a power source (battery), a path (wires), and something to power (a bulb). Current flows ONLY when the loop is complete — a single break (an open switch, a loose wire) stops everything, like a bridge missing one span.
🧠 Memory hook
Complete loop → current flows. Any break in the loop → nothing works.
😂 Giggle
Why did the wire refuse to carry the current?
It just didn't have the capacity — it was too thin and had too much resistance!
😲 Whoa!
A light switch works by simply breaking or completing the circuit loop — flicking it "off" just opens a tiny gap that stops the whole current.
✅ Quick check: Why does a bulb go out when you open a switch in its circuit?
Say your answer out loud first — then reveal.
The switch breaks the loop, so the circuit is no longer complete and current can’t flow.
Current needs an unbroken loop; a break stops it everywhere.
🧪 Try it! (2 minutes)
Make a loop with a battery, wire and small bulb; break the loop and watch it go dark.