Question

The polarities of the voltages V GS and V DD for the operation of an n-channel JFET (Junction Field Effect Transistor) as an amplifier are

A. V GS negative and V DD positive
B. V GS negative and V DD negative
C. V GS positive and V DD positive
D. V GS positive and V DD negative
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Answer 1

The polarities for V GS and V DD in an n-channel JFET for amplifier operation are negative for V GS and positive for V DD, which aligns with the way an electric field controls charge carrier flow in semiconductors.

Step-by-step explanation:

The operation of an n-channel JFET (Junction Field Effect Transistor) as an amplifier requires particular polarities for the voltages VGS and VDD. The correct polarities are that VGS should be negative and VDD should be positive, which corresponds to option A. This is because, in an n-channel JFET, a negative voltage at the gate with respect to the source (VGS) helps to deplete carriers from the channel, thus controlling the current flow through the transistor. At the same time, a positive drain-to-source voltage (VDD) permits current conduction from the drain to the source. Such configurations are related to the principle of semiconductor doping and the behavior of p-n junctions, where an electric field dictates the flow of charge carriers.