ASA Aviation Maintenance Technician General Practice Test

Voltage is the electrical potential difference that pushes charges through a circuit. Its basic unit is the volt, defined as the potential difference between two points where one joule of work is needed to move one coulomb of charge between them. The volt can also be thought of as one watt per ampere, linking it to power and current via V = I × R. In aircraft electrical systems, you’ll see voltages labeled in volts (for example, a 28-volt DC system). The other units measure current (ampere), resistance (ohm), or power (watt), which is why they are not the unit for voltage.