Explain N-channel J-FET with its transfer characteristics.

1 Answer

Answer :

Working of Channel JFET:

image


Working: 1. The application of negative gate voltage and positive drain voltage with respect to source, reverse biases the gate- source junction of an N-channel JFET. 2. When a voltage is applied between the drain & source with dc supply voltage (VDD ), the electrons flows from source to drain through the narrow channel existing between the depletion regions. This constitutes the drain current (ID ) & its conventional direction is from drain to source. The value of drain current is maximum, when no external voltage is applied between the gate & source & is designated by the symbol IDSS. 3. When VGG is increased, the reverse bias voltage across gate-source junction is increased. As a result of this depletion regions are widened. This reduces the effective width of the channel & therefore controls the flow of drain current through the channel. 4. When gate to source voltage (VGS ) is increased further, a stage is reached at which both depletion regions touch each other. 5. At this value of VGS, channel is completely blocked or pinched off & drain current is reduced to zero. The value of VGS at which drain current becomes zero is called pinch off voltage designated by the symbol VP or VGS(OFF) . The value of VP is negative for N-channel JFET. 


image

Related questions

Description : Differentiate between N-channel and P-channel J-FET.

Last Answer : N-Channel JFET P-Channel JFET 1.The current conduction takes place due to electrons 1.The current conduction takes place due to holes. 2.Its switching speed and cut off ... It is most widely used in circuit applications 5.It is comparatively less used in circuit applications

Description : Describe the operation of N channel enhancement type MOSFET with diagram.

Last Answer : As its name indicates, this MOSFET operates only in the enhancement mode and has no depletion mode. It operates with large positive gate voltage only. It does not conduct when the ... of charge carriers attracted to the positive gate. Thus drain current is controlled by the gate potential.

Description : Describe operation of N-channel JFET

Last Answer : Operation of N-channel JFET  1) When VGS = 0 volt: When a voltage is applied between the drain and source with a DC supply voltage VDD with VGS = 0 V, the electrons flow from source ... to zero. The gate to source voltage at which current reduces to zero is called as pinch-off voltage.

Description : With the help of N-channel JFET describe the effect of input voltage VGS on output current ID.

Last Answer : Working of N channel FET: * When a voltage is applied between the drain and source with a DC supply (VDD), the electrons flows from source to drain through narrow channel ... where the channel gets completely blocked and the drain current becomes zero is called pinch- off voltage. 

Description : When does the Body bias effect occur in an n-channel MOSFET?  A) When the Source voltage is less the Bulk voltage B) When the Source voltage is equal to or greater the Bulk voltage C) When the Drain voltage is equal to the Bulk voltage D) When the Gate voltage is equal to the Bulk Voltage 

Last Answer : When does the Body bias effect occur in an n-channel MOSFET?  A) When the Source voltage is less the Bulk voltage B) When the Source voltage is equal to or greater the Bulk voltage C) ... voltage is equal to the Bulk voltage D) When the Gate voltage is equal to the Bulk Voltage 

Description :  construction of P-channel J-FET.

Last Answer : Construction of P-channel J-FET : The construction diagram of P channel junction field effect transistor (JFET) is shown in above figure. It consist of a P type silicon ... enter the semiconductor bar and Source (S) is a terminal through which the electrons leave the semiconductor. 

Description : Draw the drain characteristics of p-channel FET and explain.

Last Answer : Drain characteristics:- As VDS is increased from zero as shown , ID will increased proportionally through the p channel. In this region the channel resistance is constants because the depletion region is ... the depletion layer. (i.e. channel width zero) is called cutoff voltage or VGS(off).

Description : Draw the transfer characteristics for N-channel JFET.

Last Answer : Transfer characteristics for N-channel JFET: 

Description : Pinch off voltage of a J FET is the drain to source voltage above which drain current. • Increases • Decreases • Remains constant • Becomes zero

Last Answer : Pinch off voltage of a J FET is the drain to source voltage above which drain current Remains constant

Description : A semiconductor device made up of a single p-n Junction is called a: w) transistor x) diode y) Fet z) integrated circuit

Last Answer : ANSWER: X -- DIODE

Description : Compare BJT with FET

Last Answer : FET BJT It is unipolar device i.e. current in the device is carried either by electrons or holes It is bipolar device i.e. current in the device is carried either by ... from minority- carrier storage effects & therefore has lower switching speeds & cut-off frequencies. 

Description : Compare between BJT and FET on the basis of (i) Biolar/Unipolar (ii) Tharmal Runaway (iii) Noise (iv) Applications

Last Answer : Parameter BJT FET Bipolar/Unipolar It is bipolar device i.e. current in this device is carried by electrons and holes. It is unipolar device i.e. current ... in oscilloscopes, electronic voltmeters and other measuring and testing equipment because of their high input impedance.

Description : Define pinch off voltage and drain resistance of FET.

Last Answer : 1 . Pinch-off Voltage: It is the value of the drain to source voltage VDS at which the drain current ID reaches its constant saturation value. Any further increase in VDS does not have any ... drain to source voltage to the change in drain current. It is also called AC/dynamic drain resistance.

Description : List different types of FET.

Last Answer : Types of FETs:  1. Junction FET (JFET) i. N-Channel JFET ii. P-Channel JFET  2. MOSFET i. E-MOSFET ii. D-MOSFET 

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

Last Answer : 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 ... input voltage.  Application: Buffer amplifier Low noise amplifier Cascade amplifier Chopper amplifier

Description : What is the full form of FET ?

Last Answer : The full name of FET is Field effect Transistor

Description : my adopted son has adhd and is Bipolar mixed and I have had him in and out of physc wards since he was 12, now he is 16,and failing 9th grade and apparently doesnt care.talking doesnt work taking things away ie, tv,phone privaleges,etc , Im also fet up ?

Last Answer : Bipolar disorder is a very serious MEDICAL condition, and cannot be treated by taking away phone and TV privileges. Your son is in serious need of help; seek out a well-regarded specialist A.S.A.P.

Description : Why is input impedance of the FET very high?

Last Answer : BECAUSE its input circuit (gate to source) is reverse biased and input gate current is very small.

Description : why the bjt is known as current controlled device and fet is known as voltage controlled device ?

Last Answer : Ans- 1. In BJT because of the current the output will vary. 2. Where as in FET by means of Voltage the output is varied.

Description : An FET has a gate source bias of 2 V. The ac input signal is ± 1.2 V. The class of operation is A) A B) B C) C D) AB

Last Answer : D) AB

Description : Applying a reverse bias to the gate of an FET has what effect?

Last Answer : Source-to-drain resistance increases.

Description : What is the key to FET operation?

Last Answer : Effective cross-sectional area of the channel.

Description : The base of a transistor serves a purpose similar to what element of the FET

Last Answer : Gate.

Description : The FET and the vacuum tube have what in common?

Last Answer : Voltage controls conduction.

Description : What is one of the primary advantages of the FET when compared to the bipolar transistor?

Last Answer : High input impedance.

Description : State the classifications of FET devices.

Last Answer : FET is classified as 1. Junction Field Effect Transistor (JFET) 2. Metal oxide semiconductor family (MOS).

Description : In a transistor, the conventional current flows from base to emitter. The transistor is (a) NPN (b) PNP (c) FET (d) None of these

Last Answer : (a) NPN

Description : State any two applications of FET.

Last Answer : Applications of FET : As input amplifiers in oscilloscopes, electronic voltmeters and other measuring and testing equipment because high input impedance reduces loading effect to the minimum. As Constant ... Used as Analog switch. As a Voltage Variable Resistor (VVR) in operational amplifiers. 

Description : Define with respect to FET:- (i) Static drain resistance (ii) Dynamic resistance (iii) Trans conductance (iv) Pinch-off voltage

Last Answer : (i) Static drain resistance- It is the ratio of drain source voltage (ΔVDS) to the drain current (ID) at constant gate-source voltage. It can be expressed as, Rd = (VDS)/(ID) at ... of charge carrier and the value of drain current reaches its constant saturation value is called pinch off voltage.

Description : Sketch circuit diagram of common source FET Amplifier. State working principle of it.

Last Answer : Working: -  * When small a.c. signal is applied to the gate, it produces variation in the gate to source voltage. This produces variation in the drain current. As the gate to source ... and we get amplification. Thus the AC output voltage VDS is 180º out of phase with AC input voltage.

Description : Comparison of BJT and FET

Last Answer : FET BJT It is unipolar device i.e. current in the device is carried either by electrons or holes It is bipolar device i.e. current in the device is carried either by both ... is comparatively more noisy. It is relatively immune to radiation. It is susceptible to radiation

Description : State the application of FET

Last Answer : Applications of FET : * As input amplifiers in oscilloscopes, electronic voltmeters and other measuring and testing equipment because high input impedance reduces loading effect to the minimum. * As Constant ... Used as Analog switch. * As a Voltage Variable Resistor (VVR) in operational amplifiers.

Description : The gain of an FET amplifier can be changed by changing: (1) rm (2) gm (3) Rd (4) None of these

Last Answer : The gain of an FET amplifier can be changed by changing: gm

Description : A FET is preferred over an ordinary transistor because it  1. Permits high degree of isolation between input & output circuits 2. Has low noise level 3. Has very high power gain 4. Has all the above properties 

Last Answer : A FET is preferred over an ordinary transistor because it Has all the above properties 

Description : An FET is a better chopper than a BJT because it has (A) lower offset voltage (B) higher series ON resistance (C) lower input current (D) higher input impedance

Last Answer : An FET is a better chopper than a BJT because it has lower offset voltage

Last Answer : A FET is essentially a Voltage driven device

Last Answer : A FET is a Bi-polar transistor

Last Answer : In an FET One junction has reverse bias on both sides of the junction.

Description : What is the difference between BJT and FET?

Last Answer : BJT  is  a  current  opperated   transistor  while  FET   is  a  field   opperated  transistor.

Description : Is the input impedance of MOSFET more than BJT and FET?

Last Answer : Yes, the input impedance of MOSFET more than BJT and FET.

Description : What are the advantages of FET?

Last Answer : FET is a constant current device which is controlled by voltage. By varying the input voltage we can control the output current. There are basically two types of FET one is MOSFET and second is JFET . ... as compare to BJT. These are some advantages of FET (Field Effect Transistor).

Description : How many pieces of J channel in a box?

Last Answer : What is the answer ?

Description : Explain the forward bias characteristics of a P-N Junction diode. 

Last Answer : forward and reverse characteristics of P-N junction diode.

Description : Sketch construction of N-channel JFET and explain its operating principle.

Last Answer : Construction of N-channel JFET: Working of N channel FET: a)when VGS is zero,ID flows because of VDS b)Now when VGS increases towards negative, depletion layer also increases on both sides. c)so VGS control drain current ID d)so it is called as field effect Transistor

Description : The unit of heat transfer co-efficient in SI unit is (A) J/M2°K (B) W/m2°K (C) W/m°K (D) J/m°K

Last Answer : (B) W/m2°K

Description : The units of resistance to heat transfer is (A) J.m-2 .K-1 (B) J.m-1 .K-1 (C) W.m-2 .K-1 (D) W-1m2K

Last Answer : (D) W-1m2K

Description : State the Shannon Hartley’s theorem for channel capacity. Explain the effect of S/N ratio and bandwidth on channel capacity.

Last Answer : In information theory, the Shannon-Hartley theorem tells the maximum rate at which information can be transmitted over a communications channel of a specified bandwidth in the presence of noise. According to Shannon, ... value of S/N with increase in B,assuming the signal power S to be constant.

Description : The market for heavy industrial equipment is concentrated in the West Midlands, so an equipment manufacturer has decided to employ a direct sales force in that region. Which factor ... A)Buyer behaviour B)Product attributes C)Organisational objectives D)Environmental forces E)Market characteristics

Last Answer : E)Market characteristics

Description : State characteristics of communication channel. 

Last Answer : Characteristics of communication channel. 1. Bit rate 2.Baud rate 3.Bandwidth 4.Repeater distance 5.Channel capacity

Description : Finish the sequence: J F M A M J J A S O N _. What letter goes in the space? -Riddles

Last Answer : The letter D because the letters are the first letters of months: January February March April May June July August September November So the D would be December.