What does a DC voltage measurement indicate if the test leads are reversed?

When test leads are reversed during a DC voltage measurement, the result will show a negative voltage indication. This is due to the fact that in a direct current (DC) circuit, the voltage polarity is significant. The positive lead should always be connected to the higher potential point and the negative lead to the lower potential point.

If the leads are switched, the measurement will reflect a negative sign, indicating that the positive lead is now connected to what is technically the negative or lower potential side of the circuit. This is a normal and expected outcome when testing DC voltage; it helps the technician understand the voltage's polarity and the correct orientation for future measurements.

The concept of polarity is essential in DC circuits, and recognizing a negative value is critical for interpreting the voltage correctly.