What is the total voltage across a parallel circuit?

In a parallel circuit, the total voltage across the circuit is the same as the voltage across each individual component connected in that circuit. This means that the voltage remains constant across all branches, regardless of the number of components or their individual resistances.

The notation E(t) = E(1) = E(2) = E(3) encapsulates this principle, indicating that voltage remains equal across each parallel path, which is a fundamental characteristic of parallel circuits.

This understanding is crucial in fire alarm systems and other electrical installations, as it ensures that all devices operate under the same voltage, thereby allowing reliable operation and functionality. Ensuring that all components maintain the same voltage is necessary for the effective operation of alarms, sensors, and notification devices within the system. In contrast, the other choices reference relationships that pertain to series circuits or Ohm's Law inappropriately for this context.