Definition
The difference in electrical pressure between two points in a circuit, measured in volts. It is the force that pushes electrons from one point to another and is what causes current to flow when a path is provided between the two points.
Plain English
It's the electrical 'push' between two points. If one point has more electrical pressure than another, that gap in pressure is the potential difference, and it's what makes electricity move when you connect the two points.
Context Anchor
Seen in aircraft electrical system discussions, especially when measuring batteries, switches, wires, and circuit components with a meter.
Derivation
Potential' comes from the Latin potentia, meaning power or capability. In electrical terms, it refers to the stored capability to do work by moving electrons. 'Difference' simply means the gap between two values. So 'potential difference' is the gap in electrical capability between two points — and that gap is what makes electrons move.
Why Pilots Care
Low or incorrect potential difference reveals failing batteries, poor connections, or generator issues that can lead to electrical system failure in flight.
Analogy
Think of two water tanks at different heights connected by a pipe. The height difference creates pressure that pushes water through the pipe. Potential difference works the same way for electricity — the bigger the difference, the harder electrons are pushed through the wire.
Grounding Statement
A charged aircraft battery has a potential difference between its positive and negative terminals even before anything is turned on.
Intuition Check
Potential difference does not mean a possible difference that may or may not exist. In electrical work, it means a real, measurable electrical difference between two points.
Example Sentence 1
The technician measured a potential difference of 24 volts across the battery terminals, confirming it was fully charged.
Example Sentence 2
A sudden drop in potential difference along the bus bar pointed to a loose ground connection.