When testing a good diode in both directions with an ohmmeter, the readings should be

• A. Continuity in both directions
• B. Continuity in forward direction only
• C. No continuity in either direction
• D. Short circuit in reverse direction

Answer: (A)

When you test a diode with an ohmmeter, you’re checking how it conducts in different directions. A diode should conduct current in one direction (forward bias) and block it in the opposite direction (reverse bias). In forward bias, the ohmmeter measures a low resistance, showing continuity. In reverse bias, the diode blocks current, so the resistance is very high or the reading shows no continuity.

So the correct idea is: continuity in the forward direction only. If you see continuity in both directions, the diode is likely shorted. If you see no continuity in either direction, the diode is open or defective. To test correctly, connect the meter so the positive lead is on the diode’s anode and the negative on the cathode for forward bias, then swap leads to test reverse bias.