In a series DC circuit, how does current flow?

• A. The current splits into parallel paths
• B. Current is zero after first component
• C. The current flows through each component in series along the same path
• D. The current increases with each component

Answer: (C)

In a series DC circuit, there is only one path for current to take, so the same amount of current flows through every component in the loop. The charges leaving the source must pass through each element in turn, meaning the current through the first element is the same as through the next one, and so on. Ohm’s law ties this to the total resistance: with a fixed supply voltage, the current equals the voltage divided by the total resistance; adding more components in series increases total resistance and reduces the current, but it doesn’t create different currents in different parts of the loop. The current cannot split or increase as it passes through successive components, unless the circuit is altered or opened. In practice, a closed series aircraft electrical path will have the same current flowing through the source, any switches, and the load.