Electrical Circuit
Electricity and Magnetism

Varying loops

Classroom Activity for 5-11 Supporting Physics Teaching

What the Activity is for

Through working with physical loops, the children establish that when an extra bulb is added to a simple electric circuit, the bulb gets dimmer.

When an extra battery is added to a simple electric circuit, the bulb gets brighter; or the buzzer/bell sounds louder; or the motor turns more quickly.

They are then encouraged to think about their observations.

What to Prepare

  • Batteries
  • Bulbs/buzzers/bells/motors
  • Connecting leads

What Happens During this Activity

What happens when bulbs are added?

  • The children work in small groups to observe what happens with one, two and possibly three bulbs in a loop.
  • Then children are encouraged to talk and think about the electrical loop to describe what they have found with the various electric circuits.
  • The children first of all work in pairs to talk through their ideas to explain why the bulbs are dimmer and the current smaller when a second bulb is added. Pairs then report back in during class discussion.

What happens on adding a battery?

  • The children work in pairs to explore a circuit containing a bulb and then a circuit with a buzzer/bell/motor with one, two and possibly three batteries (you should check beforehand that the bulbs will survive three batteries) and observe what happens.
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