What principle ensures that the total voltage in a series circuit equals the sum of individual voltage drops?

The principle that ensures the total voltage in a series circuit equals the sum of individual voltage drops is Kirchhoff's Voltage Law. This law states that the sum of all electrical potential differences (voltage) around any closed loop in a circuit must equal zero. In a series circuit, the voltage provided by the power source is distributed among the components in the circuit. Each component has its own voltage drop, and when these drops are summed, they equal the source voltage.

This principle is crucial for analyzing series circuits, as it helps in understanding how voltage is shared among different circuit elements. By applying Kirchhoff's Voltage Law, one can solve for unknown voltages in a circuit without needing to directly measure them, thus enhancing the capability to design and troubleshoot electrical systems.