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NCERT Solutions Curiosity Chapter 3 In-text Questions — Electrical Conductors and Insulators

Book page 34 Updated on2026-09-05

Q1.
Why did we use metal wires for making electric circuits? Can we not use some other materials for wires?
Answer

Metals are used because electric current flows through them easily — metals are good conductors of electricity. Most other materials do not let current pass at all, so a circuit made with them would never work.

MaterialDoes current pass?Can it be used for wires?
Copper, silver, gold, aluminiumYes, easilyYes — these are conductors
Plastic, rubber, wood, glass, waxNoNo — these are insulators

Silver, copper and gold are the best conductors of electricity. Even so, copper is used for almost all wiring because it is much cheaper than silver or gold and is available in plenty. Different kinds of wires are made for different uses — thin ones for a torch, thick ones for a house.

Q2.
Also, why are electric wires covered with plastic or rubber?
Answer

Because plastic and rubber are insulators — current cannot pass through them. The covering keeps the current inside the metal wire where it belongs.

The covering does three jobs:

  • Protects people. Our body is a conductor. If we touched a bare wire carrying current, the current would pass through us and could cause severe injury or even death.
  • Stops short circuits. If two bare wires touched each other, current would take the short path instead of going through the device.
  • Protects the wire itself from moisture, rust and damage.
Why it happens: Conductors and insulators are both needed in every electrical device. Wires, switch contacts, plug pins and socket parts are made of conductors so that current can flow; their coverings, plug tops and switch bodies are made of rubber, plastic or ceramic so that current cannot reach our hands.
Caution: Never touch a switch or plug with wet hands, never use electrical devices in wet places, and never use equipment with damaged insulation or a broken plug.
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