Why does a bulb only light up when the wire makes a full loop?
A child finds one battery, one tiny bulb, and one loose wire, then wonders whether counting wire pieces or tracing every physical connection is what decides if a circuit can work.
Talk about it
- Guess before we close the loop: dim glow or fully dark?
- Where could a hidden break be hiding in a string of lights, and how would we find it?
- Is a light switch adding electricity, or just opening and closing a gap in the loop?