Which instrument is used for measuring electrical resistance?

The instrument specifically designed for measuring electrical resistance is the ohmmeter. This device operates on the principle of Ohm's law, which relates voltage, current, and resistance. An ohmmeter applies a small voltage to the component being tested and measures the resulting current flow, allowing it to calculate the resistance using the formula R = V/I, where R is resistance, V is voltage, and I is current.

In contrast, a voltmeter measures the voltage across a component or circuit. An ammeter measures the current flowing through a circuit, and a wattmeter quantifies power consumption by measuring both voltage and current in a circuit. While these instruments are essential in electrical measurements, they serve different functions than that of an ohmmeter, which is exclusively focused on resistance measurement.