Switched On

What's this Science Bite about?

Make your own electrical circuit and investigate ways to allow electricity to flow through it! It’s important to be careful when experimenting with electricity so please ask an adult for help before you begin.

What you'll need

An assortment of the items needed for this experiment

  • 9v battery
  • Battery lead*
  • Light emitting diode (LED)*
  • Length of plastic coated single core wire (~15cm)*
  • 2 metal drawing pins
  • A cork
  • Wire strippers

For your switch component, experiment with some of the following:

A paperclip, paper fastener, safety pin, ring pull

  • Paperclip
  • Paper Fastener
  • Safety Pin
  • Ring pull
  • Any other small metal household object!

*You can buy these components cheaply from hardware stores or from electronics suppliers.

How to do this experiment

  1. Make sure you have all your materials and a thick mat or newspaper/magazine to work on. Also make sure you have an adult close by to help. Trim the end of the wire using the wire strimmers to reveal the metal ends if necessary.
    Trimming the wire using wire strippers

  2. Gently push one of the drawing pins half way into the long side of the cork, ~1 cm from the end. Watch that you don’t prick yourself!
    A cork with wire attached to it using a pin
    Carefully wind one of the metal ends of the wire around the drawing pin and push down onto the cork to secure the wire. Push the second drawing pin half way into the cork, roughly 3 cm away, or the length of your switch component.

  3. If you look closely at the metal legs of your LED, you will see that they are slightly different lengths.
    A close up of the LED to be attached
    Bending the legs outwards, take the shorter leg and twist the metal part of the wire around it securely.

  4. Take the battery snap and clip it into place on the battery terminals. Take the black coloured wire and attach it to the second drawing pin on the cork by winding the metal part of the wire around it. Then secure the wire by pushing the pin further into the cork.
    Attached battery snap

  5. Taking the red wire of the battery lead, wind the metal part of the wire securely around the longer leg of the LED.
    Joining the red wire of the battery snap to the LED

  6. You need a switch component to complete the circuit, so choose one of the ‘switches’, e.g. a paper clip. Fix one end of your switch by looping it around one drawing pin, or secure it between the cork and pin ensuring good metal contact. Bend the component upwards slightly so that it doesn’t touch the other pin.
    Circuit with a switch attached

  7. By pressing the other end of your ‘switch’ down on the second drawing pin, you complete your circuit!
    The LED lit up when circuit completed
    If you have chosen a switch material that conducts electricity then your LED should light up!

How does it work?

The battery is a store of energy. To use this energy the components in the circuit must be connected in a complete loop and made of a substance that allows electricity to past through it. We call these substances conductors, all metals are conductors. Materials that do not let electricity through them are called insulators.

In our circuit the metal wires conduct electricity around the circuit using the energy from the battery to light up the LED.

Fun things to try!

Try making a circuit with a bell or a small motor instead of an LED to see if you can complete a simple circuit and make it work! Or why not try designing your own switch using other materials? Remember the key is that the materials you use must conduct electricity!

Curriculum Links

Electricity

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Glasgow Science Centre