FET is a ______ controlled device. (a) current (b) resistance (c) impedance (d) voltage

Field-Effect Transistor (FET)

A FET may be either

ID = IDSS (1 - VGS/VP)2 in case of JFET

Or

ID = K (VGS - VT)2 in case of MOSFET

The field-effect transistor (FET) is a transistor that regulates the flow of current in a semiconductor by using an electric field. Devices containing FETs (JFETs or MOSFETs) have three terminals: the source, gate, and drain. Since FETs operate using a single carrier type, they are often referred to as unipolar transistors. In other words, FETs operate using either holes (p-channel) or electrons (n-channel) but not both. By applying a voltage to the gate, which in turn changes the conductivity between the drain and source, FETs may regulate the flow of current. Therefore, a FET is a current source with voltage control.

Summary:

FET is a ______ controlled device. (a) current (b) resistance (c) impedance (d) voltage

A voltage-controlled FET is a device. It controls the output current as it is a voltage-controlled or driven device.