why mosfet is voltage controlled device?

by

1 Answer

Answer :

already answered here is mosfet current controlled device?

by

Related questions

MOSFET are current controlled or voltage controlled devices?

Last Answer : MOSFET  are voltage controlled devices.

is bjt a voltage controlled device ?

Last Answer : No, BJT is a current controlled device .

is igbt current controlled device ?

Last Answer : No, IGBT is not the current controlled device. IGBT is a voltage controlled device. IGBT have combine qualities of MOSFET and BJT. The high switching speed of MOSFET and low conduction losses of BJT. Also, IGBT which stands for Insulated Gate Bipolar Transistor have high input impedance.

The threshold voltage of an n- channel enhancement mode MOSFET is 0.5V when the device is biased at

Description : The threshold voltage of an n- channel enhancement mode MOSFET is 0.5V when the device is biased at a gate voltage of 3V. Pinch off would be occurs at a drain voltage of (A) 1.5V (B) 2.5V (C) 3.5V (D) 4.5V

Last Answer : The threshold voltage of an n- channel enhancement mode MOSFET is 0.5V when the device is biased at a gate voltage of 3V. Pinch off would be occurs at a drain voltage of 2.5V

why thyristor is called semi controlled device?

Last Answer : Thyristor can only be turned on by small gate pulse but it cannot be turn off by using gate hence thyristor is called semi controlled device.

Is BJT current controlled or voltage controlled?

Last Answer : BJT is current controlled device.

Justify. Power MOSFET is operated at high enough gate source voltage to minimize the conduction losses.

Description : Justify. Power MOSFET is operated at high enough gate source voltage to minimize the conduction losses. 

Last Answer : MOSFET is metal oxide field effect transistor. MOSFET is a voltage controlled device. MOSFET is majority carrier device. MOSFET are of two one is n-channel MOSFET and p-channel MOSFET. Gate, ... . Hence, power MOSFET is operated at high enough gate-source voltage to minimize the conduction losses.

is mosfet current controlled device?

Last Answer : No, MOSFET is not the curent controlled device. The current between drain and source which is drain current is controlled by applying a voltage between gate and source hence MOSFET is a voltage controlled device. 

The speed of a three-phase induction motor is controlled by variable voltage variable frequency control

Description : The speed of a three-phase induction motor is controlled by variable voltage variable frequency control (i.e. keeping V/f constant). As the frequency is reduced, the slip at maximum torque  (1) Decreases (2) Increases (3) Remains constant (4) None of the above

Last Answer : The speed of a three-phase induction motor is controlled by variable voltage variable frequency control (i.e. keeping V/f constant). As the frequency is reduced, the slip at maximum torque Increases 

A current controlled voltage source is equivalent to :

Description : A current controlled voltage source is equivalent to :  (A) series voltage feed -back amplifier (B) shunt current feed -back amplifier (C) shunt voltage feed -back amplifier (D) series current feed -back amplifier

Last Answer : A current controlled voltage source is equivalent to : shunt voltage feed -back amplifier

In voltage source converter based HVDC transmission system the active power is controlled by changing

Description : In voltage source converter based HVDC transmission system the active power is controlled by changing (A) phase angle of the converter ac input voltage (B) supply frequency of the converter ac input voltage (C) magnitude of the converter ac input voltage (D) DC voltage at the inverter terminals

Last Answer : In voltage source converter based HVDC transmission system the active power is controlled by changing phase angle of the converter ac input voltage

For a 15-bus power system with 3 voltage controlled buses, the size of Jacobian matrix is

Description : For a 15-bus power system with 3 voltage controlled buses, the size of Jacobian matrix is

Last Answer : For a 15-bus power system with 3 voltage controlled buses, the size of Jacobian matrix is 25 x 25

Describe with neat sketch the construction and working principle of MOSFET.

Description : Describe with neat sketch the construction and working principle of MOSFET.

Last Answer : Construction and working principle of MOSFET:  A) Depletion type MOSFET: Construction: The N-channel depletion type MOSFET is formed on P-type silicon substrate with two heavily ... accumulation of electrons and hence more current. Thus the MOSFET is a gate voltage controlled device.

State the applications of MOSFET

Description : State the applications of MOSFET

Last Answer : Applications of MOSFET: i) Switching-mode-power-supplies (SMPS) and linear power supplies. ii) Brushless DC motor drives iii) Solid state DC relay iv) Automobile applications v) Stepper motor controller vi) Lighting controls vii) Solenoid drivers viii) Robotics ix) Induction heating

Which phenomenon is present in thyristors but absent in BJT, MOSFET and IGBT ?

Description : Which phenomenon is present in thyristors but absent in BJT, MOSFET and IGBT ? (A) forward conduction (B) latching (C) forward blocking (D) reverse breakdown

Last Answer : Which phenomenon is present in thyristors but absent in BJT, MOSFET and IGBT ? (A) forward conduction (B) latching (C) forward blocking (D) reverse breakdown

Explain MOSFET gate drive circuit and totem pole configuration.

Description : Explain MOSFET gate drive circuit and totem pole configuration.

Last Answer : MOSFET gate drive circuit: The turning on and turning off of MOSFET can be controlled from gate to source voltage signal. If the gate to source voltage of MOSFET exceeds threshold ... this configuration, the two switches (transistors) are used in totem pole arrangement with a comparator.

Explain the formation of parasitic BJT and parasitic diode in Power MOSFET.

Description : Explain the formation of parasitic BJT and parasitic diode in Power MOSFET. Can parasitic diode be used in same power electronics applications?

Last Answer : Parasitic Diode: The parasitic diode is in between drain and source. The MOSFET structure itself contains parasitic diode or body drain diode. This parasitic diode allows the reverse flow of current when the ... of MOSFET as a BJT collector. Parasitic BJT operates in the cut-off region.

Operating frequency of power MOSFET is higher than that of power BJT. Justify the statement.

Description : Operating frequency of power MOSFET is higher than that of power BJT. Justify the statement.

Last Answer : Power MOSFET have high turning on and turning off capability high switching speed of MOSFET is due to the high rate of change of drain voltage. The switching losses of power MOSFET ... lower frequency. Hence, operating frequency of power MOSFET is higher than that of power BJT.

Justify the statement. Antiparallel diode is connected across MOSFET.

Description : Justify the statement. Antiparallel diode is connected across MOSFET.

Last Answer : In MOSFET current is flow from drain to source but when the load is inductive the current may flow in opposite direction. To avoid the opposite flow of current and to protect MOSFET the antiparallel diode is connected across MOSFET.

parallel operation of mosfet can be done more easily as compared to thyristor. why?

Description : parallel operation of MOSFET can be done more easily as compared to thyristor. why?

Last Answer : Parallel operation of MOSFET can be done more easily as compared to thyristor because the resistance of MOSFET is increases with increase in temperature. MOSFET have the positive temperature coefficient. In ... the parallel operation of MOSFET can be done more easily as compared to the thyristor.

Explain difference between enhancement MOSFET and depletion type MOSFET.

Description : Explain difference between enhancement MOSFET and depletion type MOSFET.

Last Answer : In enhancement MOSFET channel is not initially exists but in depletion MOSFET channel is already exists. In case of depletion MOSFET if the voltage is applied between drain and source the drain current will flow ... a channel. depletion MOSFET & enhancement MOSFET

Compare BJT, MOSFET and IGBT .

Description : Compare BJT, MOSFET and IGBT .

Last Answer : BJT MOSFET IGBT BJT is a current controlled device. MOSFET is a voltage controlled device. IGBT is a voltage controlled device. The input impedance of BJT is low. ... is minority carrier device. MOSFET is majority carrier device. IGBT is minority carrier device.

Explain the series and parallel operation of MOSFET. Which is suitable and why ?

Description : Explain the series and parallel operation of MOSFET. Which is suitable and why?

Last Answer : Series operation of MOSFET: To increase voltage handling capability MOSFETs are connected in series. When the MOSFETs are connected in series each MOSFET should turn on and turn off ... on and turn off time and transconductance. Each MOSFET should share current equally.  

why IGBT is preferred as a power switch over both power BJT and MOSFET?

Last Answer : Because it has a higher switching frequency and heat tolerance.

what is depletion type MOSFET?

Description : What is depletion type MOSFET?..........

Last Answer : Depletion MOSFET: Depletion MOSFET is a MOSFET in which the channel already exists. If we apply a voltage between drain and source then the drain current will flow even if the gate to source ... in figure. The drain current will be reduced as the gate to source voltage made more negative.

what is enhancement MOSFET?

Description : What is enhancement MOSFET?...............

Last Answer : Enhancement MOSFET: There are two types of MOSFET one is enhancement MOSFET and second is depletion MOSFET. In enhancement MOSFET channel is created by applying threshold voltage between gate and source ... mode. The enhancement MOSFET will not conduct if the gate to source voltage is zero.

why igbt is used instead of bjt and mosfet?

Last Answer : ON state losses of IGBT is less as compared to MOSFET and BJT.

why mosfet is used for high frequency?

Last Answer : MOSFET provides better efficiency at high frequency and its high speed switching losses are less hence MOSFET is used for high frequency.

State classification of Phase controlled rectifiers.

Description : State classification of Phase controlled rectifiers.

Last Answer : Classification of phase controlled rectifiers:

Single-phase mid-point controlled rectifier with RL load

Description : Single-phase mid-point controlled rectifier with RL load

Last Answer : Single-phase mid-point controlled rectifier with RL load : The circuit configuration of single-phase midpoint controlled rectifier is shown in the figure. During positive half-cycle of ... some part of next positive half-cycle of voltage with reversed polarity can appear across load.

Single-phase Midpoint controlled rectifier with Resistive load

Description : Single-phase Midpoint controlled rectifier with Resistive load

Last Answer : Single-phase Midpoint controlled rectifier with Resistive load:  1) During positive half cycle of AC supply, a is positive with respect to b , this makes T1 forward biased and T2 is reverse ... voltage reverses the polarity and T2 is turned off. The operation is as shown in waveforms.

Give the operation of single phase full wave bridge controlled converter with RL load with a neat diagram. Also draw its waveform.

Description : Give the operation of single phase full wave bridge controlled converter with RL load with a neat diagram. Also draw its waveform.

Last Answer : Single phase fully control bridge converter with RL load: 1. During positive half cycle of input voltage, T1 and T2 are forward biased and during negative half cycle, T3 and T4 are forward biased. Therefore, T1-T2 ... cycle till the firing of next pair of SCRs as shown in the waveform.

Draw a neat diagram of 1Ф half wave controlled converter with RL load. Give its operation.

Description : Draw a neat diagram of 1Ф half wave controlled converter with RL load. Give its operation.

Last Answer : Single phase fully controlled half wave converter:  The circuit diagram of single-phase half-wave controlled rectifier with RL load and without freewheeling diode is shown in Fig. (a). The SCR T is ... , when again pulse is applied, the SCR is turned on & the above cycle is repeated. 

A 3 -phase, fully controlled, converter is feeding power into a DC load at a constant current of 150 A, the rms

Description : A 3 -phase, fully controlled, converter is feeding power into a DC load at a constant current of 150 A, the rms value of the current flowing through each thyristor of the converter is

Last Answer : Please show the solution for this question

When the firing angle a of a single-phase, fully controlled rectifier feeding constant direct current into a

Description : When the firing angle a of a single-phase, fully controlled rectifier feeding constant direct current into a load is 30°, the displacement power factor of the rectifier is

Last Answer : When the firing angle a of a single-phase, fully controlled rectifier feeding constant direct current into a load is 30°, the displacement power factor of the rectifier is √3/2

A 230 V, 50 Hz phase controlled single-phase full-controlled SCR bridge converter draws 15 A constant dc

Description : A 230 V, 50 Hz phase controlled single-phase full-controlled SCR bridge converter draws 15 A constant dc current. If the source inductance is 3 mH, the drop in dc output voltage is (A) 4.5 V (B) 6.75 V (C) 9 V (D) 13.5 V

Last Answer : A 230 V, 50 Hz phase controlled single-phase full-controlled SCR bridge converter draws 15 A constant dc current. If the source inductance is 3 mH, the drop in dc output voltage is 9 V

The device which allows reverse power flow and withstands highest switch frequency is

Description : The device which allows reverse power flow and withstands highest switch frequency is (A) GTO (B) MOSFET (C) IGBT (D) Inverter grade SCR

Last Answer : The device which allows reverse power flow and withstands highest switch frequency is MOSFET

why bjt is called current controlled device?

Last Answer : In  BJT  there  is  movement  of   electrons  and  holes   accros  the  junctions  which  is  basicaly  current  flow.

State advantages of MOSFET.

Description : State advantages of MOSFET.

Last Answer : Advantages of MOSFET * MOSFETs provide greater efficiency while operating at lower voltages. * Absence of gate current results in high input impedance. * High switching speed. * They operate at lower ... due to lower resistance of channel. * They are easy to manufacture. * They are portable.

Compare JFET with MOSFET.

Description : Compare JFET with MOSFET.

Last Answer : Particulars JFET MOSFET 1) Type Voltage controlled device Voltage controlled device 2) Mode of operation Operates only in depletion mode Operates in depletion and enhancement ... 6) Gate connection Not isolated from substrate Isolated by SiO2 layer from substrate

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

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.

A certain power MOSFET has a maximum junction temperature specification of 1500o C, a junction-to-case

Description : A certain power MOSFET has a maximum junction temperature specification of 1500o C, a junction-to-case thermal resistance of 1.00 C/W, and a junction-to ambient thermal resistance of 600 C/W. If the ambient temperature is 300o C ... the device will be A) 1.52 W B) 1.72 W C) 1.92W D) 2.00 W

Last Answer : A certain power MOSFET has a maximum junction temperature specification of 1500o C, a junction-to-case thermal resistance of 1.00 C/W, and a junction-to ambient thermal resistance of  ... 300o C, then the maximum allowable power dissipation in the device will be 2.00 W 

When does the Body bias effect occur in an n-channel MOSFET?

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 

A MOSFET has how many terminals?

Description : A MOSFET has how many terminals?

Last Answer : A MOSFET having three terminals 1st one is Gate (insulated), 2nd one is Source and 3rd one is Drain.

What is channel length modulation in MOSFET?

Description : What is channel length modulation in MOSFET?

Last Answer : Shortening of lenght of the inverted channel region with increase in drain bias for large drain biases due to which current increases with drain bias and output resistance decreases is called channel length modulation in MOSFET.

Why Mosfet is called Mosfet?

Description : Why Mosfet is called Mosfet?

Last Answer : Why Mosfet is called Mosfet?

In MOSFET, the polarity of the inversion layers is the same as that of?

Description : In MOSFET, the polarity of the inversion layers is the same as that of?

Last Answer : In MOSFET, the polarity of the inversion layers is the same as that of majority carriers in the source.

MOSFET uses the electric field of?

Description : MOSFET uses the electric field of?

Last Answer : MOSFET uses the electric field of gate capacitance.

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

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.

is IGBT costlier than BJT and MOSFET?

Last Answer : Yes IGBT is costlier than BJT and MOSFET.