What happens to the current through a Zener diode if the input voltage increases?

When the input voltage applied to a Zener diode increases beyond its breakdown voltage, the Zener diode enters its breakdown region where it conducts current in the reverse direction. The primary function of a Zener diode in this mode is to maintain a constant voltage across it, known as the Zener voltage.

As the input voltage increases, the Zener diode will clamp the voltage to its specified Zener voltage. However, since the diode is conducting in reverse, the current through the Zener increases significantly. This is because the excess voltage over the Zener voltage causes more current to flow through the diode to maintain the voltage regulation.

This behavior allows Zener diodes to be used in voltage regulation applications, where maintaining a consistent output voltage is critical despite variations in input voltage or load conditions. Therefore, an increase in input voltage directly leads to an increase in current through the Zener diode, affirming that the correct answer is that the current increases.