If you make a mistake in polarity when measuring the value of dc voltage in a circuit with a digital vom, what will happen?

Changes the sign of the measured electrical potential

Explanation:

If you have a positive test charge with an electric field, and it moves from point A to point B, keeping the balance without exception, then the work that the agent that carries the load has to do is equal to:

Which is called electric potential difference.

This work can be a negative, positive or null value, and the electric potential corresponding to B is less, greater or equal respectively to the potential of A.

On a VOM digital multimeter the black color is always connected inside the pin or connector marked COM, short for COMMON (Common/Ground/0 V) and the red tip is connected inside the V pin (Highest electrical potential )

Let:

Also, let's assume:

So, if you meaure the voltage with the correct polarity, the VOM will show you this result:

On the other hand if you make a mistake in polarity, the VOM will show you the same result but with a different sign: