Questions: Conductors and Insulators

Question 1

Why are electrical wires usually made of copper?

• A. Copper is shiny
• B. Copper is a good conductor of electricity
• C. Copper is the cheapest metal
• D. Copper is the lightest metal

Answer: (B)

Copper is an excellent conductor, meaning it allows electric charges to flow through it very easily with little resistance.

Question 2

Rubber is a good insulator.

• T. True
• F. False

Answer: True

Rubber does not let electricity flow through it easily, which is why it is used to coat wires and make protective gloves for electricians.

Question 3

What is the purpose of the plastic coating around electrical wires?

Model answer: The plastic acts as an insulator to keep electricity from escaping the wire and to prevent shocks.

Plastic is an insulator — it blocks the flow of electricity. The coating keeps the current safely inside the metal wire.