How does a linear electronic voltage regulator work?

A linear electronic voltage regulator works by using a control element, typically a pass transistor, which acts much like a variable resistor. This transistor continuously adjusts its conduction, or resistance, in response to changes in the input voltage or the load current. By smoothly varying this conduction, the regulator drops exactly the right amount of excess voltage as heat to maintain a constant, steady voltage at the output. Because it operates in the linear region of the transistor's operating curve, it provides a very clean output with minimal noise. The distractor mentioning "duty cycle" actually describes a switchmode regulator, not a linear one. Furthermore, a linear regulator definitely requires a pass transistor, eliminating the option that claims it eliminates the need for one.