In a series circuit, which variable is additive and which remains the same?

In a series circuit, the nature of voltage and current behaves in a specific way that supports the chosen answer. In such circuits, the total voltage across the circuit is indeed the sum of the voltages across each individual component. This means that as you add more resistors or any component in series, the voltage drop across those components adds up to the total supplied voltage.

On the other hand, the current remains the same throughout all components in a series circuit. This is a fundamental principle of series circuits, where the same amount of current flows through each component because there is only one path for the current to take. Therefore, while the voltages add up, the current does not change; it remains constant regardless of the number of components present.

Understanding these characteristics of series circuits is crucial in analyzing how they function in various electronic applications, and why option A accurately reflects the behavior of voltage and current in this context.