Voltage and Field
D V = - E Ds , or Ex = -DV / Dx .
Note also the minus sign means that electric field goes from high voltage towards low voltage. Note also that this means that
positive charges will tend to “fall” from high voltage to low voltage (like masses tend to fall from high places to low places) , but that
negative charges will tend to “rise” from low voltage to high voltage (like bubbles tend to rise) !