The leads of a DMM with a diode check function are placed across the terminals of a diode and then reversed. A 0.6 volt reading is obtained in both directions. Technician A says this means the diode is shorted. Technician B says this means the diode is acceptable. Who is correct?
A) Technician A only
B) Technician B only
C) Both Technician A and B
D) Neither Technician A nor B

Question

The leads of a DMM with a diode check function are placed across the terminals of a diode and then reversed. A 0.6 volt reading is obtained in both directions. Technician A says this means the diode is shorted. Technician B says this means the diode is acceptable. Who is correct?
A) Technician  A only
B) Technician  B only
C) Both Technician A and B
D) Neither Technician A nor B

Quizplus · Accepted Answer

A diode should only conduct in one direction, showing a voltage drop (typically around 0.6V for silicon diodes) in the forward-biased direction and showing OL (overload, indicating very high resistance) in the reverse-biased direction. A 0.6V reading in both directions indicates the diode is shorted, as it is conducting in both directions, which aligns with Technician A's statement.

The Leads of a DMM with a Diode Check Function