What scale must the DMM have to test diodes not connected in a circuit?

To test diodes that are not connected in a circuit, a digital multimeter (DMM) must use the Ohms scale. This is because measuring the resistance of the diode in this manner allows for the checking of its functionality. A diode allows current to flow in one direction, and when testing it with the Ohms setting, you can determine the diode's forward and reverse resistance.

When the DMM is set to the Ohms setting, it sends a small amount of current through the diode. For a functioning diode, you would expect to see a low resistance value when the diode is forward-biased (positive lead to the anode, negative to the cathode), indicating that the diode is allowing current to pass. Conversely, when it is reverse-biased (positive lead to the cathode and negative to the anode), you should see a very high resistance, showing that the diode is blocking the current as it is intended to.

Using the DC Volts or AC Volts scales would not provide the necessary information about the diode's condition; these settings measure voltage rather than resistance. The Amperes scale measures current flow, which is not relevant when the diode is isolated from a circuit and does not provide insight into the specific characteristics