Electrician's Licensing Practice Exam

What is an ampere a measure of?

1. Resistance in a circuit

2. Voltage in a circuit

3. The amount of electric charge passing a point in a circuit per unit time

4. The power consumed by a device

The correct answer is: The amount of electric charge passing a point in a circuit per unit time

An ampere is fundamentally defined as the amount of electric charge that flows past a point in a circuit per unit time. Specifically, one ampere corresponds to one coulomb of charge passing through a given point in one second. This definition is critical for understanding electrical current, which is the movement of electrons through a conductor. In electrical circuits, the ampere measures how much electricity is flowing, which is vital for determining how components will function together and whether a particular system can handle the load without overheating or failing. Recognizing this measurement is foundational for electricians, as it allows them to assess whether the wire gauge and components used in a circuit are appropriate for the current being drawn. The other options pertain to different aspects of electrical theory: resistance relates to how much a material opposes the flow of current (measured in ohms), voltage signifies the electric potential difference that drives the current (measured in volts), and power refers to the rate at which energy is consumed or converted (measured in watts). Thus, these concepts are distinct from what an ampere measures.