Conductor or insulator?
Put different materials into the gap in a simple circuit, see whether the bulb lights, and sort them into conductors and insulators.
Core concept
Conductors let electric current flow and insulators do not; metals and graphite conduct, while plastic, rubber, glass and dry wood insulate
Topic: Electricity
A circuit: A complete loop that electricity flows around, from the cell through the bulb and back. All key words tester is a cell, a bulb and wires with a gap in them. When a material is placed across the gap, the bulb lights only if electric current: The flow of electricity through a wire, measured in amperes (A). All key words can flow through it. Materials that let current flow are conductor: A material that lets electricity or heat pass through easily, like copper. All key words: all metals, graphite (pencil lead) and salt water. Materials that do not are insulator: A material that does not let electricity or heat pass through easily, like plastic. All key words: plastic, rubber, glass, dry wood, paper and cloth. Wires are made of copper to carry the current and covered in plastic to keep it from flowing where it should not.
What you will learn
- Test materials with a simple circuit tester.
- Classify materials as conductors or insulators.
- Explain why wires are made of metal and covered with plastic.
Before you start
- Know that a bulb lights only in a complete circuit.
Materials
- Copper wire, iron nail, aluminium foil, steel spoon, a coin, pencil lead, salt water, plastic ruler, rubber band, glass rod, dry wooden stick, paper, cotton thread
Equipment
- 1.5 V cell, small bulb in a holder, connecting wires with crocodile clips
Procedure
- Choose a card and place the material across the gap in the circuit.
- Watch whether the bulb lights.
- Place each card in the conductors or insulators group.