What is necessary for outlets on 15- and 20-ampere circuits to ensure safety?

Using grounded receptacles is essential for outlets on 15- and 20-ampere circuits to ensure safety. Grounding provides a safe path for electrical current to return to the ground in case of a fault, such as a short circuit or equipment malfunction. This significantly reduces the risk of electric shock and helps to prevent electrical fires that can occur due to faulty wiring or devices that may cause currents to flow where they shouldn't.

Grounded receptacles are designed to accept a grounding wire and have a third slot for the grounding pin, which connects to the grounding system of the electrical installation. This grounding feature ensures that if an electrical device becomes faulty, the ground connection will redirect the current safely away. Therefore, the installation of grounded receptacles is a critical safety measure in residential wiring, making it the correct choice for ensuring the safety of outlets on these circuits.