Question

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

Answer 1

Answer:

Changes the sign of the measured electrical potential

Explanation:

If you have a positive test charge $q_o$ 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:

$V_B-V_A=V_B_A=\frac{W_A_B}{q_o}$

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:

$V_B=Highest\hspace{3} electrical\hspace{3} potential\\V_A=Lowest\hspace{3} electrical\hspace{3} potential$

Also, let's assume:

$V_B=12V\\V_A=1$

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

$V_B-V_A=V_B_A=12-1=11V$

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

$V_A-V_B=V_A_B=1-12=-11V$

Answer 2

 Nothing happens. Just reverse the probes of multimeter & measure it again, this time around it should come positive