State and explain the working principle of FET amplifier and list its applications.

State and explain the working principle of FET amplifier and list its applications.
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1 Answer

Answer :

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Operation of FET amplifier: When small a.c. signal is applied to the gate, it produces variation in the gate to source voltage. This results in variation in the drain current. As the gate to source voltage increases, the drain current also increases. As the result of this, the voltage drop across resistor (RD) also increases. This causes the drain voltage to decrease. It means positive half cycle of the input voltage produces the negative half cycle of the output voltage. (ie. ) the output voltage is 180° out of phase with the input voltage. 

Application:

Buffer amplifier

Low noise amplifier

Cascade amplifier

Chopper amplifier

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