What do you connect an ohmmeter to when testing its functionality?

When testing the functionality of an ohmmeter, it is important to connect it in series with the component you are testing to measure the resistance accurately. This connection allows the ohmmeter to pass a small test current through the component and measure the voltage drop across it, which is necessary for calculating resistance according to Ohm's Law (R = V/I).

Connecting the ohmmeter in series ensures that you can obtain a clear reading of the component's resistance without interference from parallel paths or existing voltage sources. This method is essential because when in series, the current flowing through the component is solely dictated by the resistance of that component, allowing for an accurate resistance measurement.

In contrast, the other options would not provide accurate functionality testing for the ohmmeter. For example, connecting it directly to the power source would risk damaging the meter by exposing it to high voltage. Connecting it in parallel with the component or across the circuit does not allow the ohmmeter to function correctly, as it wouldn't accurately measure resistance. Instead, it would read other voltage levels or interfere with the current flowing through the circuit.