What does the black probe of a circuit tester typically connect to?

The black probe of a circuit tester is commonly connected to the neutral wire. In electrical testing, the neutral wire is typically regarded as the return path for current and is usually at ground potential. By connecting the black probe to the neutral wire, the tester can measure voltage potential relative to the ground efficiently.

In many testing scenarios, the red probe is connected to the live or hot wire, allowing a comparison of voltage readings between these two points. Understanding the roles of the neutral and live wires is crucial for safely diagnosing and managing electrical systems. The neutral wire tends to carry current back to the power source, while the ground wire provides a safety path for current to prevent shock hazards. Knowing this helps clarify the function of the black probe in circuit testing.