Definition
A wire-wound resistor that has one or more electrical connections, called taps, brought out from intermediate points along its resistance element. These taps allow a circuit to draw off a fixed portion of the total resistance rather than the whole value.
Plain English
A resistor with extra connection points along its length, so a circuit can use part of the resistor instead of all of it.
Context Anchor
Seen in aircraft electrical circuits, instrument circuits, and maintenance wiring diagrams where one resistor may provide more than one resistance path.
Derivation
Tap comes from the old idea of tapping into a barrel to draw off some of its contents. In electrical use, a tap draws off part of the resistance at a chosen point along the wire.
Why Pilots Care
Provides precise fixed resistance steps needed for reliable operation of cockpit lighting dimmers and certain voltage control circuits.
Analogy
Think of a long hose with extra outlets along its length. Using an outlet near the start is different from using one near the far end. A tapped resistor gives a circuit similar choice points along one resistive part.
Intuition Check
Tapped does not mean the resistor has been struck or damaged. Here it means an extra electrical connection has been made partway along the resistor.
Example Sentence 1
The instrument panel dimmer used a tapped resistor so the pilot could select different brightness levels.
Example Sentence 2
During troubleshooting the dimmer circuit, the mechanic found that one tap on the resistor had become intermittent.