When using a Volt Ohm Meter (VOM) to measure resistance, you should:

When using a Volt Ohm Meter (VOM) to measure resistance, you should:

• A. Keep the component in the circuit and measure
• B. Remove the component from the circuit
• C. Power the circuit and measure high current
• D. Disconnect power and measure across supply

Answer: (B)

To measure resistance with a VOM, the circuit must be de-energized and the component isolated so the meter’s test current passes only through that component. When the component is removed from the circuit, you get the true resistance without parallel paths through other components or power sources altering the reading. If you leave the component in the circuit, other resistors or wiring can skew the measurement, giving an inaccurate value. Turning the circuit on while measuring resistance is unsafe and can damage the meter, since ohm readings rely on a small, internal current and require no power in the circuit. Measuring “across the supply” would not reveal the component’s resistance and could still involve live power, which is dangerous. So removing the component from the circuit before measuring is the correct approach.

To measure resistance with a VOM, the circuit must be de-energized and the component isolated so the meter’s test current passes only through that component. When the component is removed from the circuit, you get the true resistance without parallel paths through other components or power sources altering the reading. If you leave the component in the circuit, other resistors or wiring can skew the measurement, giving an inaccurate value. Turning the circuit on while measuring resistance is unsafe and can damage the meter, since ohm readings rely on a small, internal current and require no power in the circuit. Measuring “across the supply” would not reveal the component’s resistance and could still involve live power, which is dangerous. So removing the component from the circuit before measuring is the correct approach.