1. Electrical conductors
and insulators

2.  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.

3. Do all materials allow electricity to flow
through them?
What kind of materials allow electricity
to flow through them?

4. Identify electrical conductors and
electrical insulators.

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

6. Heat conductors are materials that allow
heat to pass through it easily.
Examples: Metals - silver, iron, copper, aluminum.
Silver Copper

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

8. What types of materials are good electrical
conductors?
Alumiuium? Rubber? Wood?

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

10. What types of materials are electrical
insulators?
Glass? Pencil lead?

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

12. Step 1: Set up the circuit Step 2: Place the object
tester as shown above. between the open ends of the
wire or crocodile clips.

13. 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.

14.  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.

15.  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

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

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