Clickory

Classroom mode

Run it in class

Why does a bulb only light up when the wire makes a full loop?

Show of hands — before you project anything

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.

  • A Way more than you'd guess
  • B About what you'd guess
  • C Way less than you'd guess

Count the votes out loud. Hold them to it — then watch.

Project it (fullscreen)

Discussion prompts

  • 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

A prediction-first worksheet — no answer key.

zero prep · no login · any projector

Winding down at home? Family mode · Explore every question