Which of the following materials is a good example of an insulator?

• A. Metal
• B. Rubber
• C. Wood
• D. Glass

Answer: (B)

Rubber is a well-known example of an insulator due to its ability to resist the flow of electric current and heat. Insulators are materials that do not allow electricity or thermal energy to pass through them easily. This property is crucial in many applications, such as electrical wiring, where rubber is often used as a protective covering to prevent accidental shocks and to ensure the safe functioning of electrical devices.

While metals are excellent conductors of electricity and heat, materials like wood and glass can have insulating properties to a certain extent, but they are not as effective as rubber in most practical applications. Using rubber as an insulator helps to improve safety and energy efficiency in various settings.