How do FETs primarily differ from BJTs?

The key distinction between FETs (Field Effect Transistors) and BJTs (Bipolar Junction Transistors) lies in how they control the flow of current. FETs utilize an electric field generated by voltage at the gate terminal to manage the current flowing between the source and drain terminals. This mechanism allows FETs to operate primarily as voltage-controlled devices, making them responsive to the voltage input and leading to higher input impedance.

In contrast, BJTs are current-controlled devices. They require a certain amount of base current to allow a proportionally larger current to flow from the collector to the emitter. This fundamental difference is crucial as it influences both the power consumption and the operational characteristics of these transistors.

The other options present misconceptions. While both FETs and BJTs can be made from silicon, they are not limited to a single type of semiconductor material, and the materials can vary based on specific applications. In terms of power requirements, FETs often have lower power consumption due to their higher input impedance and lower biasing needs compared to BJTs. Although both types of transistors can be utilized for amplification and switching, each has its own advantages and ideal scenarios, making the blanket statement in one of the choices inaccurate.