What instrument would you use for checking the resistance of a circuit?

An ohmmeter is the appropriate tool to use for checking the resistance of a circuit. This instrument is specifically designed to measure electrical resistance in ohms. When connected to a circuit or component, it supplies a small amount of current and measures the voltage drop across the component, allowing it to calculate the resistance based on Ohm's Law (R = V/I).

Using an ohmmeter is essential for troubleshooting electrical circuits, as it can help identify faulty components or connections by indicating whether they have the expected resistance values. This distinguishes it from other instruments:

An ammeter measures the current flowing through a circuit. A wattmeter measures the power consumed in a circuit, and a voltmeter measures the voltage across a component. Each of these instruments serves distinct purposes and is not suitable for measuring resistance directly. Therefore, the ohmmeter's function as a resistance measurement tool makes it the correct choice for this question.