Nate Electrical Practice Exam

What indicates a capacitor is functioning properly when tested with an ohmmeter?

1. The needle moves quickly to the right and slowly returns

2. The needle moves slowly to the right and drops suddenly

3. A spark is observed when a lead is removed

4. No voltage is measured across its terminals

The correct answer is: The needle moves quickly to the right and slowly returns

The correct indication of a capacitor functioning properly when tested with an ohmmeter is when the needle moves quickly to the right and slowly returns. This behavior demonstrates that the capacitor is initially charging when the leads of the ohmmeter are connected. The rapid movement of the needle indicates a low resistance, showing that the capacitor allows current to flow as it charges up. The needle then moving slowly back signifies that the capacitor has reached its peak charge, after which it starts discharging through the ohmmeter, registering an increasing resistance as it discharges its charge. This behavior is consistent with the expected operation of an electrolytic capacitor where a brief initial surge of current is observed as it charges, followed by a gradual return to a higher resistance state when it becomes fully charged. Therefore, this test process highlights the capacitor's ability to hold a charge, indicating it is functioning properly.