Technologies K–10 · Years 5–6

Conductor or insulator: choosing materials for a switch

Material World (NSW Science and Technology K–6, 2017); Design and Technologies: Knowledge and understanding, Technologies context: Materials and technologies specialisations (ACARA v9)

PracticalLow risk

The idea

Metals let electric current pass and most non-metals do not, so a designer picks a metal for the parts of a switch that must carry current and an insulator for the parts people touch.

What you need

The LED circuit from the LED activity (2 AA cells, 100 Ω resistor, LED) with a gap closed by two alligator-clip probes
Test items: aluminium foil, steel paper clip, copper wire, brass key, 20c coin, graphite pencil core exposed at both ends, plastic ruler, wooden pop stick, rubber band, glass marble, paper, dry cotton string
Card, 2 split pins and a paper clip for building a switch

How to do it

Touch the probes together: the LED lights. This is the control.
Clip the probes to each item in turn and record: bright, dim or off.
Sort the items into conductors and insulators and look for a pattern.
Design a switch from card, split pins and a paper clip, choosing materials from the results.
Test the switch in the circuit 10 times on and 10 times off.

What you should see

The metals (foil, paper clip, copper, brass, 20c coin) light the LED brightly. The graphite core also lights the LED: graphite is a non-metal that conducts, with more resistance than a metal, so a long core can make the LED slightly dimmer. Plastic, wood, rubber, glass, paper and dry string leave it off, matching Primary Connections: copper, iron and steel are good conductors and plastic, wood, glass and rubber are good insulators. The switch works when the paper clip bridges the two split pins, all 10 times. The learner knows it worked when the control lights the LED and every metal sits in the conductor group.

What changes

What you change: the material placed between the probes
What you measure: LED brightness (bright, dim, off)
What you keep the same: the same cells, resistor and LED
the same probe spacing
clean contact surfaces

Common misconceptions

Each of these ideas is wrong, and the activity is a chance to test it.

All metals are equally good conductors (they differ, though all light this LED).
Pencil 'lead' is lead metal (it is graphite, a form of carbon, which conducts).
Insulators are useless in circuits (switches, cables and plugs need insulators to be safe).

Safety card

Low riskLearners carry it out

Hazards

Sharp foil edges
Pencil core snapping

Controls

Fold foil edges; handle cores gently

Note

Low-voltage cells only. Record the activity on Primary School RiskAssess (riskassess.com.au).

Curriculum references

The NSW syllabus outcomes and Australian Curriculum v9 codes this activity supports. They are references, not a verified or complete curriculum alignment.

Science and Technology K–6 Syllabus (2017), NESA. The syllabus taught in 2026; the 2024 syllabus replaces it from 2027. Code read from the official syllabus document (DOCX) on 2026-09-22.ST3-7MW-T ST3-2DP-T
Science and Technology K–6 Syllabus (2024), NESA. Implementation from 2027, so this code describes the future syllabus. Code read from the Stage 3 content page on 2026-09-22, where its focus area names this fair test of electrical conductors and insulators and the part insulators play in electrical safety.ST3-SCI-01
Science and Technology K–6 Syllabus (2024), NESA. Implementation from 2027, so this code describes the future syllabus. Code read from the Stage 3 content page on 2026-09-22; the entry is a fair test with the variables it lists.ST3-PQU-01
Science and Technology K–6 Syllabus (2024), NESA. Implementation from 2027, so this code describes the future syllabus. Code read from the outcomes page on 2026-09-22. It covers the switch design and test steps only.ST3-DDT-01
Australian Curriculum v9AC9TDE6K05

Sources

The pages the author read to write this activity.

All Concept Studio activities