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Everyday Machines / Week 06 / Tuesday
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Week 06 · The Light Switch

Tuesday

The loop
// A loop, a gap and a glow
⏱ about 15 min

Tuesday: The Loop

Rocket holds a flashlight. A grown-up has put in two small batteries.

He slides the switch. The bulb glows.

Raven turns it over. "What do you notice inside the handle?"

Nova glows a ring of light around the flashlight. "It is a loop."

A circuit is a loop

Electricity needs a complete path to flow.

That complete path is called a circuit.

The path goes from the battery, through the bulb, and back.

If there is a gap, the electricity stops.

The switch is a gate

A switch closes the loop. The light turns on.

A switch opens a gap in the loop. The light turns off.

Every light switch in your home works this way.

Inside a flashlight

  • A battery pushes the electricity.
  • A bulb turns the electricity into light.
  • A switch closes the loop or opens a gap.
  • A metal strip joins the parts into one loop.
TURN THE LIGHT ON
  • Tap a card.
  • Then tap its spot.
1First
2Next
3Then
4Last
LOOP OR GAP?
  • Read the question.
  • Tap your answer.
The switch closes the loop. What happens?
The switch opens a gap. What happens?
What is a circuit?
Try it
Hold a flashlight your grown-up has loaded.
Slide the switch on. Slide it off.
Say loop when it is on and gap when it is off.
Do it five times.
Safety first
Use a flashlight with AA or smaller batteries only.
A grown-up puts the batteries in and takes them out.
Batteries never go in your mouth. Keep them from little kids.
No wires to the wall. Nothing goes in an outlet.
SentenceTrue or false?
Electricity needs a complete loop to flow.?
A gap in the loop turns the light on.?
The battery pushes the electricity.?
The bulb turns electricity into light.?
WHY THIS EXERCISEEvery switch in your home is a gate in a loop.
FLASHLIGHT PARTS
  • Read the question.
  • Tap your answer.
Which part pushes the electricity?
Which part joins the parts into one loop?
Draw a loop: battery, switch, bulb, and back to the battery.

You found the loop hiding in every switch!

Tomorrow, we look inside a flashlight.

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