Which device is specifically designed to measure electrical resistance?

The device specifically designed to measure electrical resistance is the ohmmeter. An ohmmeter operates by sending a small current through a component and measuring the voltage across it, allowing it to calculate the resistance based on Ohm's Law (R = V/I). This is essential for identifying the resistance of various components, like resistors or wire, in electrical circuits.

In contrast, other options serve different functions in an electrical system. An ammeter measures current, a voltmeter measures voltage, and a wattmeter measures power. Each of these devices plays a crucial role in electrical diagnostics, but only the ohmmeter is focused strictly on resistance measurement.