NEIEP Mechanics Practice Exam

Which statement is accurate regarding voltage in a circuit?

1. Voltage is the rate of flow of electric charge

2. Voltage is the potential difference between two points

3. Voltage determines the type of current

4. Voltage is a measure of resistance

The correct answer is: Voltage is the potential difference between two points

Voltage is accurately described as the potential difference between two points in a circuit. This means it represents the energy per unit charge that is available to push electric charges through a conductor. When we say there is voltage between two points, it indicates that there exists an electric field that can cause charge carriers, such as electrons, to move from one point to another, ultimately resulting in electric current. Understanding voltage as a potential difference helps to clarify how electrical devices function. For instance, in a battery, the difference in electric potential energy between the positive and negative terminals creates a driving force that causes current to flow in the circuit when it is closed. This concept is foundational to circuit theory and is key to analyzing how circuits operate, whether they are simple series or complex parallel arrangements. The other statements do not accurately describe voltage: the rate of flow of electric charge refers to current, while voltage does not determine the type of current, and it is not a measure of resistance, which is defined by Ohm's Law as the ratio of voltage to current.