How should an ohmmeter be connected to get a proper reading?

Connecting an ohmmeter across a resistor that is disconnected from the circuit voltage source ensures that you get an accurate measurement of the resistance without interference from other components in the circuit. When a resistor is still part of a circuit and connected to a voltage source, there may be other paths for current to flow, which can lead to misleading readings.

By disconnecting the resistor, you isolate it from any voltage present in the circuit, allowing the ohmmeter to measure only the resistance of the resistor itself. This is vital because an ohmmeter sends a small current through the resistor to measure how much resistance it provides, and if the resistor is still connected to a live circuit, this can cause incorrect readings or potential damage to the meter.

Additionally, measuring resistance in series with a resistor or parallel to the main circuit would also yield inaccurate readings due to the influence of other circuit elements or voltage present. The key focus is on achieving a clean measurement by ensuring the resistor is disconnected from any power source.