What do ohmeters measure in a circuit or component?

• A. Voltage
• B. Current
• C. Resistance
• D. Power

Answer: (C)

Ohmeters are specialized instruments designed to measure the resistance in a circuit or component. Resistance is a property that quantifies how much a device opposes the flow of electric current, typically represented in ohms. When using an ohmeter, one can determine how easily current can pass through a material or component, which is crucial for diagnosing issues in electrical circuits.

This measurement is essential for understanding the functionality of various components, as excessive resistance can indicate problems such as poor connections or damaged parts. Ohmeters work by applying a known voltage across the material and measuring the resulting current to calculate resistance based on Ohm's Law (V = IR), where V is voltage, I is current, and R is resistance. Thus, they do not measure voltage, current, or power directly, which is why the other options are not applicable in this context.