Which material is commonly used for electrical insulation?

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

Answer: (B)

Rubber is commonly used for electrical insulation due to its excellent properties that prevent the flow of electricity. It has a high dielectric strength, which allows it to withstand high voltages without breaking down and allowing current to pass through. This makes it an ideal choice for insulating wires and cables, as it effectively protects against electrical shock and short circuits. Additionally, rubber is flexible, durable, and resistant to abrasion, moisture, and heat, making it suitable for various environmental conditions where electrical insulation is necessary.

While wood can be a natural insulator, it's not as reliable as rubber for electrical applications, mainly due to its susceptibility to moisture and changes in its insulating properties under varying environmental conditions. Metal, on the other hand, is a conductor of electricity and is not suitable for insulation. Glass does have some insulating properties, but it is heavier and more brittle compared to rubber, which limits its practical use in many electrical applications.