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

Determine the induced voltage at full load, A 100-kW, 250-V shunt generator...

A 100-kW, 250-V shunt generator has an armature-circuit resistance of 0.05  and a field- circuit resistance of 60 . With the generator operating at rated voltage, determine the i

Control system, I need some help for doing the assignment

I need some help for doing the assignment

Compute the efficiency at one-half load, Q. A certain 10-hp, 230-V motor ha...

Q. A certain 10-hp, 230-V motor has a rotational loss of 600 W, a stator copper loss of 350 W, a rotor copper loss of 350 W, and a stray load loss of 50 W. It is not known whether

Dc generator, A 20kw 220v shunt generator has armature resistance of 0.07 a...

A 20kw 220v shunt generator has armature resistance of 0.07 and a shunt field resisitance 900 ohm find field loss?

Electronic Devices, To demonstrate a practical method of testing semiconduc...

To demonstrate a practical method of testing semiconductor diodes.

Show the amenability to computer processing, Q. Show the Amenability to com...

Q. Show the Amenability to computer processing? Due to the digital data collected and stored in the form of a matrix, the same becomes amenable to processing on computers. By f

Explain fourth group of 32 ascii character code, Explain Fourth group of 32...

Explain Fourth group of 32 ASCII character code? The fourth, and final, group of 32 ASCII character codes are set aside for the lower case alphabetic symbols, five additional

Generation and control of electron beam, Illustration the basic working pri...

Illustration the basic working principle, process parameters, economics, safety precautions and applications of plasma Arc Machining process(PAM) Discuss Electron Beam Machining

Explain source encoding or data compression, Q. Explain Source encoding or ...

Q. Explain Source encoding or data compression? The sequence of binary digits from the source encoder, known as the information sequence, is passed on to the channel encoder. T

Phase shifter, Hi, I just finish writing my project literature review and ...

Hi, I just finish writing my project literature review and my supervisory asked me to add one part. This part is about Phase Shift. How phase shifters work? In Particular How the

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