Kirchhoff's Current Law for a series circuit states that the current entering any point in a circuit must __________ the current exiting the same point.

• A. Equal
• B. Greater
• C. Less
• D. Not Related

Answer: (A)

At a junction, current is conserved. In a series circuit there’s only a single path for current, so the same current flows through every component. If more current entered a point than left, charge would accumulate there, which DC steady-state circuits do not allow. Therefore the current entering equals the current exiting at that point. An everyday way to see this is to imagine a battery and two components in a row: the same current travels through the battery, then through each component in turn. In contrast, currents can split in parallel, but the total into the node still equals the total out. So the missing word is equal.