What is the result of correctly connecting a properly rated zener diode across a power supply load?

A properly rated zener diode, when connected across a power supply load, serves the primary function of voltage regulation. This means it will maintain a constant output voltage, effectively limiting the output DC voltage to its breakdown voltage level. When the input voltage exceeds this specified level, the zener diode allows excess current to flow through it, preventing the voltage across the load from exceeding the zener voltage.

This capability to regulate the voltage ensures that electronic components connected to the load receive a stable voltage, thus protecting them from potential damage due to overvoltage conditions. The zener diode effectively clamps the voltage, allowing for consistent operation of the load even with varying input voltages—making it an essential component in power supply circuits where voltage stabilization is necessary.

The other options do not accurately describe the function of a zener diode in this application, as it does not specifically lower the input voltage, increase load current, or shut off the power to the load. It maintains a steady output voltage by limiting variations, fulfilling its designated role in the circuit.