Conductors and insulators — Physical education, 7–10 years
Some materials let electric current pass easily; others make a barrier. This helps us choose materials for wires and for safe coverings.
Idea
A conductor is a material through which electric current can move easily. Metals such as copper and aluminium are good conductors. An insulator resists the movement of current; plastic, rubber and dry wood are common examples.
Why
Electric devices need a path that carries current to the parts that use it. Engineers put conducting metal inside wires, then cover it with an insulating material so the current stays on its path. This idea helps electricity work while reducing unwanted contact and shocks.
Worked example
To test a material in a low-voltage classroom circuit, replace a metal link with a coin. The bulb lights, so the coin conducts. Replace the coin with a plastic ruler; the bulb goes out, so the ruler blocks the current. Never test unknown objects with mains electricity.
Common trap
A common mistake is thinking that every object either conducts perfectly or never conducts at all. This is reasonable because classroom tests usually give a bright bulb or no light. In reality, materials differ in how well they conduct, and a weak connection can make a good conductor seem useless.
In the world
A cable uses copper or another conductor inside and plastic or rubber outside. The metal carries current, while the covering helps stop current reaching people or nearby objects. Handles on electrical tools are also made from insulating materials, though safety rules still matter.
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