North Carolina Building Contractor License Practice Exam

Electric hand tools must be either double insulated or what?

1. Grounded

2. Low voltage

3. Battery operated

4. Wired directly to power

The correct answer is: Grounded

Electric hand tools must be either double insulated or grounded to ensure safety during operation. Grounding provides a pathway for electrical current to safely dissipate in the event of a fault, such as a short circuit, which can significantly reduce the risk of electric shock. Double insulation is a design feature that provides two layers of protection against electrical shock, eliminating the need for a ground connection. However, when double insulation is not used, grounding becomes essential. This requirement ensures that tools are safe to use in a variety of environments and helps protect both the user and the tool itself. While low voltage, battery operated, and wired directly to power may serve specific functions or applications, they do not inherently provide the necessary safety equivalent to grounding for tools that are not double insulated. Hence, grounding remains the correct alternative safety measure for electric hand tools in this context.