In a regulated power supply, what type of component will most likely be used to establish a reference voltage?

In a regulated power supply, a Zener diode is commonly used to establish a reference voltage due to its unique characteristics. A Zener diode operates in reverse bias and is designed to maintain a constant voltage across its terminals when a specified current flows through it. This property makes it ideal for setting a stable reference voltage in voltage regulation circuits.

When the input voltage varies, the Zener diode can keep the output voltage at the desired level, assuming that the current remains within its specified limits. This helps ensure that the output voltage remains stable despite fluctuations in input voltage or load conditions, which is a crucial requirement for regulated power supplies.

Other components have different purposes: resistors are typically used for current-limiting and voltage division rather than for establishing a fixed voltage reference; capacitors are used for filtering and smoothing output, not for setting reference voltage; and transformers primarily step-up or step-down voltage levels without providing a fixed reference voltage.