A(n) __________ is used to measure resistance.

An ohmmeter is designed specifically for measuring electrical resistance, which is a fundamental property of materials that opposes the flow of electric current. The device applies a known voltage to the resistor and then measures the current that flows through it, using Ohm's Law (V = I * R) to calculate the resistance. This measurement is crucial in various electrical and electronic applications, such as troubleshooting circuits, ensuring proper component operation, and verifying the integrity of circuits.

In contrast, an ammeter is used to measure current in a circuit, while a voltmeter measures voltage across components. A flow meter, on the other hand, is typically used for measuring the flow rate of liquids or gases, which is a completely different application from measuring electrical resistance. Thus, the ohmmeter is the appropriate instrument in the context of measuring resistance.