The output impedance of a MOSFET is:

Question

Question

This question was previously asked in

RRB ALP Electronics Mechanic 21 Jan 2019 Official Paper (Shift 3)

Answer 1

Metal Oxide Silicon Field Effect Transistors (MOSFET)

qImage4118

It is a voltage-controlled three-terminal device that is used for switching and amplification purposes.
The terminals are the drain, gate, and source.
MOSFETs are of two classes: Enhancement mode and depletion mode. Each class is available as an n-channel or p-channel.
The voltage at the gate controls the operation of the MOSFET. In this case, both positive and negative voltages can be applied to the gate as it is insulated from the channel.
With a negative gate bias voltage, it acts as a depletion MOSFET while with a positive gate bias voltage, it acts as an Enhancement MOSFET.
The output impedance of the MOSFET is very high ideally infinite for a common source and common gate configuration.
The output impedance of the MOSFET is a low value for common drain configuration.