Making circuits

A conductor is a material which allows electricity to flow through it.

• True

• False

All metals are conductors of electricity

• True

• False

Here is a list of some materials.

Copper

Glass

Sand

Iron

Paper

Wood

Plastic

Which of these materials will conduct electricity?

• Copper and sand

• Iron and wood

• Paper and plastic

• Copper and iron

Here are diagrams of four electric circuits.

How many of these circuits will NOT work?

• 1

• 2

• 3

• 4

Choose the best word to complete the following sentence.

Graphite is a good electrical................................................

• Metal

• Conductor

• Insulator

• solid

Here is a diagram of an electric cable. Electric cables contain wires. The materials labelled A and B are made of plastic. Plastic is used to cover the wires because,

• Plastic is flexible and a good conductor

• Plastic is inflexible and a good insulator

• Plastic is flexible and a good insulator

• the material is not plastic but actually rubber.

Alifaiz and Almas set up a circuit , as shown in the diagram, and record how much light the bulbs are giving off. They then add an extra bulb to the circuit. The bulbs will now....

• Give off the same amount of light.

• Will give off much more light

• Will give off much less light.

• Will give off no light, as they have set up the circuit incorrectly.

Ingkar is doing an experiment where she changes a part of an electric circuit. She sets up a circuit as shown in the diagram with a short, thin piece of copper wire and closes the switch. She then measures the brightness of a bulb as bright. In the second experiment she does not close the switch. The brightness of the bulb will be...

• Bright

• Very bright

• Dim

• Bulb not on

She then takes out the second bulb and changes the wire to a short, thick piece of wire. Will the bulb shine....

• Bright

• Very bright

• Dim

• Not shine at all

She then adds the second bulbs again and closes the switch. Will the bulbs shine...

• Bright

• Very bright

• Dim

• Not shine at all