Electrical conductors and

insulators

An electric circuit is a path along which current flows.

Current can only flow through a closed circuit.

Battery provides energy in a closed circuit and current transports energy from the battery to the bulb.

Do all materials allow electricity to flow through them?

What kind of materials allow electricity to flow through them?

Identify electrical conductors and electrical insulators.

Infer that good conductors of electricity are generally good conductors of heat.

Heat conductors are materials that allow heat to pass through it easily.

Examples: Metals - silver, iron, copper, aluminum.

Silver Copper

Electrical conductors are materials that allow electric current to flow through.

What types of materials are good electrical conductors?

Alumiuium?

Rubber? Wood?

Electrical insulators are materials that do not allow electric current to flow through.

What types of materials are electrical insulators?

Glass? Pencil lead?

Use of a circuit tester: To test whether the material is a good electrical conductor.

Example of a circuit tester

Step 1: Set up the circuit tester as shown above.

Step 2: Place the object between the open ends of the wire or crocodile clips.

If the bulb lights up, it means the material allows electric current to flow through the closed circuit.

The brighter the bulb, the better the conductor of electricity is the material.

Place the two aluminum plates into the liquid tested.

If the bulb lights up, a closed circuit is formed, allowing current to flow through it.

The liquid is a conductor of electricity.

Electrical conductors are materials that allow electric current to flow through. Examples: salt water, metals such as copper, aluminium and non-metals like graphite (a form of carbon).

Copper Aluminium Graphite

Good electrical conductors are generally good heat conductors. Examples: steel, iron

Electrical insulators are materials that do not allow electric current to flow through. Examples: plastics, wood, rubber, glass.

plastic rubber