Which instrument is used to measure resistance in a circuit?

The appropriate instrument for measuring resistance in a circuit is an ohmmeter. This device is specifically designed to determine the resistance of an electrical component or circuit by measuring how much current flows through the component when a known voltage is applied. The unit of measurement for resistance is Ohms, which is directly referenced in the term "ohmmeter."

While a multimeter can also measure resistance, it is a more versatile tool that can perform multiple functions, including measuring voltage and current, in addition to resistance. Therefore, while a multimeter can certainly accomplish the task of measuring resistance, the most precise answer for an instrument solely dedicated to this task is the ohmmeter. An ammeter measures current, and an oscilloscope is used for visualizing voltage waveforms over time, neither of which are suitable for measuring resistance directly.