Final answer:
Neither Technician A nor Technician B is correct. A diode with infinite resistance in both directions indicates an open circuit within the diode, signifying it is defective and unable to conduct electricity in either direction.
Step-by-step explanation:
If a diode has a reading of infinite ohms in both directions, it is not functioning correctly. When a diode is measured with an ohmmeter, we expect it to show low resistance in the forward-biased direction (anode positive, cathode negative) and high resistance when reverse-biased. However, 'infinite ohms' suggest that no current can flow in either direction, which typically indicates an open circuit within the diode, meaning that the internal connection within the diode is broken. Therefore, neither Technician A nor Technician B is correct because Technician A mistakenly interprets this condition as a short when it is actually an open, and Technician B is incorrect in saying the diode is in good condition when it is actually faulty.
A good diode should show low resistance when forward-biased because this demonstrates the diode's ability to conduct current when the correct polarity is applied. Specifically, when a positive voltage greater than 0.7 V is applied to the anode relative to the cathode, the diode allows current to flow. When the diode is reverse-biased (anode negative, cathode positive), it should exhibit very high resistance, prohibiting current flow until the breakdown voltage is reached.
Thus, a diode that measures infinite resistance in both the forward and reverse bias indicates that the diode is defective and has an open circuit, not a short circuit as Technician A has stated, and is not in working order as Technician B has suggested.