Q1.
Suppose, we make wires of materials other than metal and use them for making the electrical circuit. Do you think the electric current will pass through those materials in such a circuit?
Answer
Not through most of them. Current will pass only if the material happens to be a conductor.
- If the 'wire' is made of a metal such as copper, aluminium or iron — yes, current passes and the lamp glows.
- If it is made of plastic, rubber, wood, glass, wax, paper or cloth — no, current does not pass and the lamp stays dark.
- A few non-metals are exceptions. Pencil lead (graphite) is not a metal but it does conduct, so the lamp glows dimly with it.
The only honest way to find out for any given material is to test it — which is exactly what the tester in Activity 3.11 is for.