What is a jumper?

• A. A fuse used to protect circuits.
• B. A conductor used to connect pins on a controller or device.
• C. A component that senses temperature.
• D. A network switch.

Answer: (B)

A jumper is a small conductive link used to configure hardware by shorting two pins on a header. It usually comes as a tiny plastic block (the shunt) that you place across two adjacent pins on a controller or device. When the jumper is in place, it bridges those pins and tells the device to enable a specific option, set a voltage level, select an address, boot in a particular mode, and similar settings. If you remove the jumper, those pins aren’t connected and the option stays in its default state. This is different from a fuse, which protects circuits by opening when too much current flows, a temperature sensor that detects heat, or a network switch that routes data.