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A megohmeter is specifically designed to measure high resistance, typically in the range of megohms. It is commonly used in electrical testing to determine the insulation resistance of cables, equipment, and components. By applying a high voltage to the circuit, the megohmeter can accurately assess how much resistance is present, which helps identify potential insulation failures that could lead to short circuits, electrical leakage, or other hazards.

The ability to measure high resistance is crucial for ensuring that electrical systems are safe and reliable, particularly in scenarios where insulation can degrade over time or due to environmental conditions. This tool plays a vital role in maintenance and troubleshooting by providing insights into the integrity of the electrical insulation.

The incorrect options involve measurements that do not fall within the megohmeter's intended use. Voltage refers to the electrical potential difference between two points, while current measures the flow of electrical charge. Low resistance is not the focus of a megohmeter, as this instrument is specifically calibrated to assess resistance at much higher values, distinguishing it from devices that measure lower resistances directly, such as ohmmeters.