Which materials are poor conductors?

• A. Rubber, plastic and wood.
• B. Copper, gold and aluminium.
• C. Water containing dissolved salts.
• D. Steel.

Answer: (A)

Materials that are poor conductors resist the flow of electricity because they have very few free electrons that can move easily. Rubber, plastic and wood fit this description, so they’re insulators and don’t let electric current pass readily. This is why they’re commonly used to coat or handle electrical devices in beauty therapy, helping to protect you from shocks.

In contrast, metals like copper, gold, and aluminium have many free electrons that move quickly, making them excellent conductors. Water with dissolved salts contains ions that can move and carry charge, so it conducts electricity as well. Steel, being a metal, also conducts electricity. So the materials that are poor conductors are rubber, plastic and wood.