When the resistance of a series circuit decreases, the total current:

In a series circuit, the total current is determined by the total voltage of the power source and the total resistance using Ohm's Law, which states that current (I) is equal to voltage (V) divided by resistance (R) (I = V/R). When the resistance of the circuit decreases while the voltage remains constant, the denominator in the equation becomes smaller. This leads to an increase in the value of current.

A decrease in resistance allows more current to flow through the circuit since there is less opposition to the flow of electric charge. Therefore, as resistance decreases, the total current increases. This concept is fundamental in understanding circuit behavior and is a key principle in electronics and electrical engineering.