Electrician's Licensing Practice Exam

Which component is least likely to be directly grounded in a residential electrical system?

1. Water pipe

2. Ground rod

3. Service entrance

4. Chassis of appliances

The correct answer is: Chassis of appliances

In a residential electrical system, the chassis of appliances is the component least likely to be directly grounded. This is because appliances are typically designed to operate safely without requiring a direct ground connection. Instead, the grounding mechanism is often achieved through the third prong of a standard plug, which connects to the grounding system of the house when plugged into an outlet. In contrast, water pipes are usually bonded to the residential grounding system to help ensure electrical safety by providing a low-resistance path to ground, especially in the event of a fault. Ground rods are specifically installed as part of the grounding system to dissipate electrical surges into the earth. The service entrance includes various overhead or underground components designed to provide primary grounding for the entire electrical system of the building. Each of these elements is intrinsically linked to the overall grounding strategy, which aims to reduce the risk of electric shock and equipment damage.