Year 4 Science: Conductors and insulators: the tester
Part of the Year 4 Science switches, conductors and insulators chapter. Chapter overview · whole chapter on one page
Conductors and insulators: the tester
A conductor is a material that lets electricity flow through it. An insulator is a material that does not let electricity flow through it.
We can test a material with a conductor tester. It is a loop with a cell, a bulb and two clips. The material goes between the two clips. If it is a conductor, the material completes the loop and the lamp lights. If it is an insulator, the lamp stays off.
Key ideas
- A conductor lets electricity flow through it, so the lamp lights in the tester.
- An insulator does not let electricity flow, so the lamp stays off.
- The conductor tester uses a cell, a bulb holder and two clips.
- Only cells and a bulb holder are used in school tests, with a grown-up.
Method. Read what the lamp shows.
- Read the result. A lamp that lights means the loop is complete.complete
- Name the material. So the material is a conductor.conductor
- Write the answer. conductor
Check. The material completed the loop. ✓
Method. Read what the lamp shows.
- Read the result. A lamp that stays off means the loop is not complete.not complete
- Name the material. So the material is an insulator.insulator
- Write the answer. insulator
Check. The insulator does not let the electricity through. ✓
Method. Look at the picture of the tester.
- Look at the lamp. The lamp in the tester is the bulb, drawn as a circle with a cross inside.bulb
- Name the part. So the lamp is the bulb.bulb
- Write the answer. bulb
Check. The bulb is the lamp that lights. ✓
Watch out
Watch out: the tester checks whether a material lets electricity flow through it. A material that is hard, shiny or heavy is not automatically a conductor.
Try it at home or school (with a grown-up). With a grown-up, make a tester with a cell, a bulb holder and two wires with clips. Test a coin and a plastic ruler, one at a time, between the clips. Say which one lights the lamp.
Exam tip
Grown-up tip. Ask: “Does the lamp light? Is the material a conductor or an insulator?” Let your child predict the result before each test.
Exercise 10B Conductors and insulators: the tester
Method. Read the definition in section 10.2.
- Read the definition. A conductor lets electricity flow through it.conductor
- Write the answer. conductor
Check. A conductor completes the loop. ✓
Method. Read the definition in section 10.2.
- Read the definition. An insulator does not let electricity flow through it.insulator
- Write the answer. insulator
Check. An insulator keeps the loop broken. ✓
Method. Read the result.
- Read the result. The lamp lights, so the loop is complete.complete
- Name the material. A material that completes the loop is a conductor.conductor
- Write the answer. conductor
Check. A lit lamp means a conductor. ✓
Method. Read the result.
- Read the result. The lamp stays off, so the loop is not complete.not complete
- Name the material. A material that keeps the loop broken is an insulator.insulator
- Write the answer. insulator
Check. An insulator keeps the loop broken. ✓
Method. Read the key idea in section 10.2.
- Read the key idea. A conductor completes the loop, so the lamp lights.lights
- Write the answer. lights
Check. A complete loop lights the lamp. ✓
Method. Look at the picture of the tester.
- Look at the picture. The lamp is drawn as a circle with a cross inside.circle with a cross
- Name the part. That symbol is the bulb.bulb
- Write the answer. bulb
Check. The bulb is the lamp. ✓
Method. Read the definition in section 10.2.
- Read the definition. A conductor lets electricity flow through it.lets electricity flow
- Write the answer. yes
Check. Conductors complete the loop. ✓
Method. Read the definition in section 10.2.
- Read the definition. An insulator does not let electricity flow through it.does not
- Write the answer. no
Check. Insulators keep the loop broken. ✓
Method. Look at the picture of the tester.
- Look at the picture. There is one clip on each side of the gap.one on each side
- Count them. So there are 2 clips.2
- Write the answer. 2
Check. The material goes between the two clips. ✓
Method. Think about the result.
- Think about the lamp. A lit lamp means the loop is complete.complete
- Decide. A material that completes the loop is a conductor, so Sam is not right.no
- Write the answer. no
Check. A lit lamp shows a conductor. ✓
Method. Think about a fair test.
- Think about the test. Only the material should change; the cell, the bulb and the clips must stay the same.stay the same
- Write one thing. For example, use the same cell each time.same cell
- Write the answer. Accept any one thing, such as: the same cell, the same bulb, or the same clips.
Check. Change only the material to keep the test fair. ✓
Method. Think about the lamp.
- Think about the lamp. The lamp lights only when the electricity can flow.can flow
- Write the reason. So the lamp shows whether the material completes the loop.completes the loop
- Write the answer. Accept any sentence that says the lamp lights only when electricity flows, so it shows whether the material completes the loop.
Check. The lamp is the evidence of a complete loop. ✓