Why does a bulb only light up when the wire makes a full loop?
Open for the projector Present it step by step
Classroom mode
A question for the whole room
One story to open. A room full of ideas to test.
Ready in three steps
- Open the story.Read and try the first pages together.
- Pause for a prediction.At the story’s question, read its choices aloud. Invite a vote and ask, “What makes you think that?”
- Run it. Watch. Wonder.Choose the class’s prediction, run the experiment, and compare what happened with your guesses.
Different guesses are welcome. The experiment gives everyone something to rethink.
Something to put on paper
A one-page prediction and observation sheet. No answers included.
After the experiment: discussion notes
Talk about what happened
- Predict first: if I cut the loop on the side away from the bulb, does the bulb stay lit, go dim, or go off? Defend your guess, then we test it.
- Why can charges only keep moving if the path returns all the way to the battery? Use the marbles-in-a-tube picture.
- What makes a short circuit dangerous, and how is a deliberate gap (a switch) different from an accidental one (a loose wire)?
Where it shows up in real life
- A holiday or fairy light string that goes dark when one bulb is pulled or burns out
- Flicking a wall switch on and off — the switch is just a gap you open and close
- A flashlight that won't light when the battery is loose or put in backwards
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