Why fet is a voltage sensitive device, Electrical Engineering

Assignment Help:

Q. Why FET is a voltage sensitive device explain from the drain characteristics?

The JFET consists of a thin layer of n-type material with two ohmic contacts,the source S and the drain D ,along with two rectifying contacts ,called the gates G .If a positive voltage is placed between drain and source,electrons will flow from source to drain .This conducting path between the source and the drain is called a channel.

Consider holding the drain source voltage fixed and varying the gate-source voltage .As the gate-source voltage is made negative ,the gate channel  pn junction is   reverse biased ,increasing the depletion red\gion between the gate and source .This decreases the channel width ,increasing the channel resistance.if the drain-source voltage  VDS is kept constant   ,the current IDS  decreases .when the gate-source voltage  is  made positive,the depletion region decreases until,for large positive gate-source voltages ,the channel opens .then the pn- junction  between gate and channel  becomes  forward biased and current flows from the gate to the source current Summarizing we find that varying the gate voltage varies the channel width ,and hence the channel resistance  .This  inturn  varies the current from drain to source,IDS .We see that it is the gate-source voltage variation which varies IDS ; thus the FET is a voltage sensitive device ,compared with the junction transistor , which is a current sensitive device.


Related Discussions:- Why fet is a voltage sensitive device

What are transmission bridges, Q. What are transmission bridges? How do the...

Q. What are transmission bridges? How do they assist in satisfying the connectivity?  Ans: A typical transmission bridge is demonstrated in figure. Series capacitance and shunt

Explain protected mode interrupt, Explain protected mode interrupt. In...

Explain protected mode interrupt. In this mode, interrupts have exactly similar assignments as in real mode, but the interrupt vector table is not same. In place of interrupt

Determine the circuit of three transistors dynamic ram cell, a. Determine t...

a. Determine the circuit of three transistors dynamic RAM cell and define briefly read and write functions. b. Write short note on factors influencing choice of layer for wiring

Which are the different fet amplifiers, Q. Which are the different FET ampl...

Q. Which are the different FET amplifiers? A FET can be used as a small-signal amplifier by connecting one of its lead to signal ground. The other two leads then serve as the i

Display the segment on the pic trainer, Aim: The aim of this practical ...

Aim: The aim of this practical is to work with multiplexed 7-segment displays and implement a counter and display the 7- segment on the PIC trainer. Equipment: PIC

Two byte instructions , Two byte  Instructions In these  instruction ...

Two byte  Instructions In these  instruction the first byte  specifies  the operations code  and the  second byte  specifies the operand. To identify  two byte  instructions o

Chemistry, write a note on vulcanization

write a note on vulcanization

Activities to preparing long-term plans, Activities to Preparing Long-term ...

Activities to Preparing Long-term Plans 1. Data collection regarding existing loads, forecast of expected loads, operating conditions, and etc. from Grid substation up to cons

Three phase induction motors - motor control , Three Phase Induction Motors...

Three Phase Induction Motors A three  phase induction rotor  consists  a stators  and a motor stator has balanced three  phase  winding. These windings  are distributed in the

How do you find the insulation resistance of transformer, Q. How do you cal...

Q. How do you calculate the insulation resistance of transformer and what is the minimum value? Ans. The insulation resistance of the transformer will be calculated by using

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd