What is the name of the side of a silicon diode that has a line on it?

The side of a silicon diode that has a line on it is known as the cathode. This marking indicates the direction of conventional current flow through the diode. In a typical diode symbol, the cathode is the terminal where current exits when the diode is forward-biased. When the diode is connected in a circuit, current flows from the anode (the unmarked side) to the cathode (the marked side) when the diode is turned on.

Understanding the functionality of the cathode is essential, as it helps in identifying the proper orientation when installing the diode in a circuit. The incorrect choices are components relating to transistors or other circuit elements rather than diodes. The emitter and collector are terms used for bipolar junction transistors, while the anode refers to the positive side of the diode, which is different from the cathode.