Semiconductor devices that have three or more electrodes describes what?

Semiconductor devices that have three or more electrodes describes what?

• A. Transistor
• B. Diode
• C. Vacuum Tube
• D. Regulator

Answer: (A)

Three-terminal semiconductor devices are transistors. They use a small control input at one terminal to regulate a larger current between the other two terminals. In a bipolar junction transistor, the terminals are emitter, base, and collector; in a field-effect transistor, they are source, gate, and drain. The base (or gate) acts as the control signal, so a little voltage or current at that terminal can switch or amplify the current flowing from emitter to collector (or from source to drain). Diodes have only two terminals, so there’s no separate control input to modulate conduction. Vacuum tubes aren’t semiconductors, even though they can have several electrodes. Regulators may have three pins, but the description points to the transistor as the standard three-terminal semiconductor device that controls current.

Three-terminal semiconductor devices are transistors. They use a small control input at one terminal to regulate a larger current between the other two terminals. In a bipolar junction transistor, the terminals are emitter, base, and collector; in a field-effect transistor, they are source, gate, and drain. The base (or gate) acts as the control signal, so a little voltage or current at that terminal can switch or amplify the current flowing from emitter to collector (or from source to drain).

Diodes have only two terminals, so there’s no separate control input to modulate conduction. Vacuum tubes aren’t semiconductors, even though they can have several electrodes. Regulators may have three pins, but the description points to the transistor as the standard three-terminal semiconductor device that controls current.