What does Kirchhoff's Current Law state?

Kirchhoff's Current Law states that the total current entering a junction in an electrical circuit must equal the total current leaving that junction. This principle is based on the conservation of electric charge, which asserts that charge is neither created nor destroyed in an electrical circuit. Therefore, at any point (or junction) where current paths converge, the sum of currents flowing into that point must be equal to the sum of currents flowing out.

This law is essential for analyzing complex circuits, as it allows for the calculation of unknown currents in various branches of the circuit. By applying this law, one can resolve the flow of electricity in systems where multiple pathways exist, ensuring that the overall charge is balanced.

In contrast, other options relate to different laws or principles in electrical theory. The law that states the voltage in a closed loop must equal zero is related to Kirchhoff's Voltage Law. The total resistance statement concerns series and parallel circuits rather than current flow. Lastly, the ratio of voltage to current being constant refers to Ohm’s Law, which applies to resistive components but does not describe current behavior at junctions.