NEIEP Mechanics Practice Exam

In a parallel circuit, what remains constant across all branches?

1. Current

2. Resistance

3. Power

4. Voltage

The correct answer is: Voltage

In a parallel circuit, the voltage across each branch remains constant. This is a fundamental characteristic of parallel circuits, where all components are connected across the same two nodes, ensuring that they experience the same potential difference. Because the voltage is the same in each branch, individual components can have different resistances and thus carry different currents. This allows for the overall current in the circuit to be the sum of the currents through each parallel branch. Power, which is dependent on both voltage and current, will vary in each branch according to the individual characteristics of each component. Resistance can differ for each branch, meaning it is not constant across the circuit. Therefore, the correct understanding of parallel circuits emphasizes that the consistent factor throughout all branches is the voltage.