Which of the following is NOT a reason to disconnect power before measuring resistance?

• A. To Prevent Damage To The Meter
• B. To Avoid Electrical Shock
• C. To Obtain An Accurate Measurement
• D. To Ensure The Circuit Remains Energized

Answer: (D)

When you measure resistance, you want the reading to reflect only the component’s resistance, not any currents or voltages from a live circuit. The meter applies a small current through the part and measures the resulting voltage drop to calculate resistance. If power is on, other sources can drive current through the path, giving a distorted, meaningless reading and potentially stressing the meter’s input. Disconnecting power also reduces the risk of electrical shock and protects the meter from damage that can occur if live voltage is present on the measurement terminals. So keeping the circuit energized is not a valid reason for measuring resistance; it undermines accuracy and safety.