To safely measure resistance, the circuit should be __.

• A. Energized
• B. De-energized
• C. Shorted
• D. Isolated

Answer: (B)

Measuring resistance requires a path for the meter’s test current, but without any external power influencing the reading. When you measure, the ohmmeter injects a small current and calculates resistance from the voltage drop. If the circuit is energized, that power source can push current into the meter and the reading becomes unreliable or could cause damage and safety hazards. De-energizing removes all active power and stored energy (like charged capacitors), so the reading reflects only the component’s resistance, not the rest of the powered network. Once the circuit is confirmed de-energized, you can place the meter across the component (disconnecting one end if needed to avoid parallel paths) to get an accurate value.