NLC Electrical Grid 2 Practice Test

In a series circuit, there is only one path for the current to take, so the same amount of charge flows through every component in that loop. The current is the rate of flow of electrons, and with a single path, what goes through one element must go through the next and the next in the same amount per second. That’s why the current through each component is the same. The overall current is set by the supply voltage and the total resistance in the loop: I = V / R_total. When you add more components in series, the total resistance increases, which lowers the current in the loop, but the current that does flow passes through each component identically. If the circuit is ever opened, no current flows anywhere. So the reason the current is the same through all components in a series circuit is that there’s only one path for the charge to flow and charge conservation ensures a single consistent current throughout that path.