Q. Working of Field-effect transistors?

Field-effect transistors (FETs) may be classified as JFETs (junction field-effect transistors), depletion MOSFETs (metal-oxide-semiconductor field-effect transistors), and enhancement MOSFETs. Each of these classifications features a semiconductor channel of either n-type or p-type, whose conduction is controlled by a field effect. Consequently, all FETs behave in a similar fashion. The FET classification is illustrated in Figure along with the corresponding circuit symbols. FETs have the useful property that very little current flows through their input (gate) terminals.