What is the primary use of a Zener diode?

The primary use of a Zener diode is voltage regulation. Zener diodes are designed to allow current to flow in the reverse direction when the voltage exceeds a certain level, known as the Zener voltage. This characteristic makes them particularly effective in maintaining a stable output voltage despite variations in the input voltage or changes in load conditions. When connected in reverse bias to a power supply, the Zener diode clamps the voltage to its designated Zener voltage, providing a regulated output that is essential in power supplies and other applications where stable voltage is critical.

In contrast, the other options relate to functions that are typically managed by different components. Current amplification usually involves transistors, signal modulation is more aligned with the functions of capacitors and inductors in communication circuits, and rectification refers to the conversion of AC to DC, commonly performed by standard diodes rather than Zener diodes. Thus, the utilization of Zener diodes in voltage regulation is a fundamental principle in electronics to ensure consistent and reliable operation of circuits.