ARRL Technician Practice Exam

What are the names of the two electrodes of a diode?

1. Anode and cathode

2. Positive and negative

3. Source and drain

4. Emitter and base

The correct answer is: Anode and cathode

In the context of a diode, the two electrodes are known as the anode and cathode. The anode is the terminal where the current enters the diode, and the cathode is where the current exits. This nomenclature is crucial because it defines the direction of current flow that the diode allows. When a diode is forward-biased, the anode is at a higher voltage than the cathode, which enables current to flow through the diode. If the diode is reverse-biased, the anode is at a lower voltage, preventing current from flowing. Understanding these terms is fundamental when discussing diode operation in electronic circuits. The other terms mentioned in the choices simply do not apply to the function or structure of a diode. Positive and negative usually refer to charge in a more general sense but do not specify the roles of the electrodes. Source and drain are associated with field-effect transistors, while emitter and base refer to different parts of a bipolar junction transistor. Thus, anode and cathode specifically define the two electrodes of a diode.