What is cable insulation?

• A. Material surrounding conductors that resists electrical current and protects against shocks and faults.
• B. A device that stores charge.
• C. The outer jacket only.
• D. A conductor itself.

Answer: (A)

Cable insulation is the dielectric material that surrounds electrical conductors. Its job is to resist the flow of electricity through unintended paths, keeping current contained within the conductor and protecting people from shocks and faults. It also provides the dielectric strength needed to prevent arcing at operating voltages and helps maintain safe spacing under heat, moisture, and mechanical stress. The insulation isn’t the outer jacket alone, and it isn’t a device that stores charge or the conductor itself—the jacket is a protective outer layer, while insulation is the insulating material surrounding the conductor.