MOSFET Question & AnswersAugust 4, 2021 By WatElectronics This article lists 100 MOSFET MCQs for engineering students. All the MOSFET Questions & Answers given below includes solution and link wherever possible to the relevant topic.A FET (Field Effect Transistor) is a class of transistors that overcomes the disadvantage of the BJT transistor. It is capable of transferring high quantity resistance to low quantity resistance and exhibits unipolarity. It comprises of 3 main terminals source, drain, and gate. Where the source is the input terminal, the gate is the controller of FET and the drain is the external terminal. It is classified into two 2 types namely JFET and MOSFET, where JFET is further classified as n-type and p-type JFET, and MOSFET is also classified as N-type Enhancement MOSFET and P-type Enhancement MOSFET. Where these FETs are biased in two ways either fixed, self, or potentially biased.In a fixed bias, the FET is connected to the battery externally for its operation, and in self-bias, it does not require any external battery to operate and in a potential bias, the bias is provided by an external source and is divided using resistors. A FET usually operates in 4 main regions ohmic, saturation, cutoff region, and breakdown region. It has certain disadvantages like higher resistance at the drain & slow operation. To overcome this, a MOSFET is designed. These can be used in both analog and digital monolithic Integrated circuits as active components and distinct devices. It is manufactured with 'controlled oxidation of the semiconductor typically using silicon.1). What are the disadvantages of Field Effect Transistors? Higher resistance at drain Operation is slow Impedance at input is moderate All as mentioned earlier HintTo overcome the disadvantages of FET2). Who introduced ‘First Vertical Power MOSFET’? Mohammed Atalla Dawon Kahng Hitachi a & b HintHitachi in 19693). What does MOSFET stands for? Metal Oxide Semiconductor Field Effect Transistor Modern Oxidized Silicon based Field Effect Transistor Modern Oxidized Silicon based Force Effect Transistor Metal Oxide silicon Field Equivalent Transistor HintTo overcome the drawbacks of FET4). What type of a device is MOSFET? Current-controlled Voltage-controlled Voltage-controlled Current source Voltage-controlled Voltage source HintCurrent at the drain can be controlled by the voltage5). What type of carriers are controlled in a MOSFET? Majority Minority Both Majority & Minority Either Majority or Minority HintBased on the type of MOSFET6). How many terminals does a MOSFET possess? One Two Three Four HintSource, gate, and drain7). What are the main terminals that carry current? Source Drain Source & Drain Gate HintTerminals Source and the Drain8). What type of MOSFETs preferred for Power electronics? Enhancement Depletion P-channel Depletion N-channel Depletion Hint‘N-channel’ made Enhancement MOSFETs9). Which layer isolates terminal Gate from semiconductor? Silicon oxide Silicon dioxide Silicon Silica HintSilicon dioxide (Thin layer) is used to isolate the gate10). MOSFET is a __________ device. Tri-terminal Unipolar Voltage-controlled All as mentioned earlier HintMOSFET is a Voltage controlled deviceRead More About MOSFET11). Which transistor is preferred for applications of High power? BJT UJT MOSFET JFET HintMOSFETs are commonly used12). What type of transistors are commonly used in digital and the analog circuits? BJT UJT MOSFET JFET HintMOSFETs are preferred13). ____________ are normally referred to as ON switches. JFET UJT Depletion MOSFET Enhancement MOSFET HintWith the terminal gate open a non-zero current at drain tends to flow14). Which substrate does a n-channel made device possess? P-type N-type Both P & N-type Can’t say HintP-type made substrate15). Which Transistor is used in VLSI? JFET UJT MOSFET CMOS HintCMOS offers low consumption of power16). Which transistor offer highest speed? JFET UJT MOSFET CMOS HintCombination of both ‘N-channel’ and ‘P-channel MOSFETs17). What is required to switch OFF the MOSFET (Depletion type)? VGS VDS VGD Either VDS or VGD HintON switches18). Which one is referred to as Open switch? JFET UJT Depletion MOSFET Enhancement MOSFET HintEnhancement mode MOSFETs are OFF19). Unbroken Line in the symbol of MOSFET known as _____ MOSFET. Depletion Enhancement ON switch (normally) a& c HintDepletion mode of MOSFETs20). What is represented by the line amid Source and Drain? Conductive channel Non-conductive channel Semi conductive channel Any type of channel HintSemi-conductive channel of the transistor21). What happens to line of channel in Enhancement MOSFETs? Broken Unbroken Dotted a & c HintEnhancement, it is broken22). What differentiates ‘N-type’ and ‘P-type’ MOSFETs? Arrow direction Line in MOSFET Mode Data insufficient HintType of channel MOSFETs23). In which class does MOSFETs work as amplifier? Class-A Class-B Class-C Class-D HintMOSFETs belong to Class-D24). At VGS =0, what happens to the channel of Depletion MOSFETs? Conduct Doesn’t conduct Rarely conduct Insulate HintON Switches25). In which MOSFET the channel gates depleted for –VGS ? P-channel Enhancement N-channel Enhancement P-channel Depletion N-channel Depletion HintDepletion MOSFETMOSFET MCQs with Answers26). In which MOSFET the channel gates depleted for +VGS ? P-channel Enhancement N-channel Enhancement P-channel Depletion N-channel Depletion HintDepletion MOSFET27). What type of MOSFETs possess Undoped or Lightly doped channel? Depletion Enhancement ON switch (normally) a& c HintEnhancement MOSFETs is nonconductive28). What condition makes MOSFET a Transconductance device? VGS> VTH VGS<VTH VGS=VTH VGS= 0 HintN-channel Enhancement MOSFET29). Transistor is OFF in P-channel eMOSFET for? +VGS -VGS VGS<VTH VGS= 0 HintPositive voltage of Source and Gate30). What are the different regions MOSFET operate? Cut-off Linear Saturation All as mentioned earlier HintThree regionsRead More About P-Channel MOSFET31). What is the condition of Cut-off region? VGS> VTH VGS<VTH VGS=VTH VGS= 0 HintCut-off must satisfy VGS<VTH32). What do you name MOSFET with n-channel? PMOS CMOS NMOS Bi CMOS HintBased on a variant of channel33). What condition satisfies Saturation region? VGS> >VTH VGS<VTH VGS=VTH VGS= 0 HintAmplification34). MOSFET in Cut-off region works as _______. Close switch Open switch Amplifier Switch Hint MOSFETs are usually OFF in this region35). What is the condition of Linear region? VGS>VTH VGS<VTH VGS=VTH VGS= 0 HintSwitching36). In which region MOSFETs perform ‘Switching’? Cut-off Linear Saturation b & c HintSaturation region in MOSFETs37). Depletion mode MOSFETs can operate in __________ mode. Enhancement Depletion Enhancement and Depletion Can’t say HintD-MOSFETs can operate in both modes38). Which substrate used in MOSFETs of n-channel? P N P+ N+ Hint Amid two n-regions39). Where the Metallic gate is deposited in MOSFETs? Substrate Electrodes Oxide layer Terminals HintThe 'oxide layer is an insulator40). MOSFET is _______. Unidirectional Bidirectional Unipolar b & c HintBidirectional and have unipolar characteristics41). In which region IDS & VDS are dependent? Cut-off Ohmic Saturation a & c HintAn increase in VDS results in an increase in IDS42). MOSFETs as Amplifiers operate in which region? Cut-off Ohmic Saturation a & c HintIDS & VDS are dependent on the Ohmic region43). Of which region IDS remains constant? Cut-off Ohmic Saturation Linear HintVDS increase doesn’t affect the value of IDS44). Which is known as Control terminal in MOSFET? Source Drain Gate Body HintGate terminal in MOSFET45). When are MOSFETs are preferred? Low voltage High Frequency a and b High voltages HintLow voltages and for high-frequency applications46). Which determine the rise & fall timings of voltage at drain? Input capacitor Gate resistance Resistor Transfer capacitor HintTransfer capacitor is known to determine the fall and rise times47). What are used in MOSFETs to determine current fall and rise timings while switching? Input capacitor Gate resistance Resistor a & b HintCapacitor at input along with Gate resistance48). What can destroy Gate Oxide Layer? Static charge Dynamic charge Random Charge Either static or dynamic HintWith proper discharging and grounding49). What happens to MOSFET in safe area of operating? Doesn’t change in Forward bias Doesn’t change in Reverse bias a & b Change in Forward and Reverse bias HintSOA MOSFET doesn’t change under any Reverse and forward biasing50). Why Switching delays occur in MOSFET? Finite Charging Time Finite Discharging Time Finite Discharging and Charging Time Data insufficient HintFinite discharging and charging times of o/p & i/p capacitorsMOSFET Interview Questions & Answers51). What are the majority carriers in n-channel MOSFET? Holes Electrons Holes & Electrons Protons HintN-channel52). MOSFETs doesn’t undergo ___________. Breakdown First breakdown Second breakdown No breakdown occurs HintBJTs53). What happens to the Leakage current in MOSFET? Small Large Very small Very large HintLeakage currents are very less54). What is the minimum amount of voltage required to operate MOSFET? Positive voltage Negative voltage Threshold voltage Breakdown voltage HintMinimum required to make the MOSFETs conduct55). What type of device is MOSFET? Active device Passive device Reactive device Neither a nor b HintPassive element in the circuit56). Which MOSFET doesn’t have channel? Depletion type Enhancement type P-Channel N-Channel HintEnhancement variant of MOSFET57). What happens to noise in MOSFET? High Low Moderate Large HintNoise in MOSFET is less58). What happens to width of channel when negative voltages applied at gate of MOSFET? Less Very less Moderate Large HintCut-off region59). Enhancement MOSFET operates in _____ modes Conducting Non-Conducting Conducting and Non-conducting Partially conducting HintBased on input voltages applied60). What happens to Transconductance in MOSFETs compared to BJTs? Low Very Low Moderate Large HintMOSFETs possess a very low value of Transconductance61). Amplifiers made of Depletion MOSFETs resembles _____. BJT amplifiers FET amplifiers JFET amplifiers b & c HintJFET and DMOSFETs62). On what MOSFET working depend? MOS Transistor MOS Capacitor MOS Resistor MOS Voltage HintMOS capacitor is considered to be essential63). Which type of voltage induce channel in ‘n-channel’ Enhancement MOSFET? Positive voltage Negative voltage Threshold voltage Zero voltage HintPositive voltage applied at the gate64). How the channel’s conductivity enhanced in E MOSFET? Decrease in VGS Increase in VGS Constant VGS Zero VGS HintVGS enhances the conductivity of the channel65). What happens to channel in EMOSFET if VGS applied is below threshold? Enhanced conductivity Conductivity is high No channel detected Channel is fixed HintNo channel66). Depletion MOSFET conducts when_______. VGS>VTH VGS<VTH VGS>0 VGS= 0 HintMOSFETs are ON67). LD MOSFET is an acronym of? Laterally Diffused MOSFET Linearly Dependent MOSFET Linearly Diffused MOSFET Linearly Doped MOSFET HintVariant of Enhancement MOSFET68). Which device has short channel? JFET BJT UJT LDMOSFET HintMOSFET69). What type of transistors are scaled to small dimensions? BJT FET UJT MOSFET HintMOSFETs in comparison to other transistors70). MOSFET is also referred to as ________. FET UJT MESFET IGFET Hint Insulation of terminal gate from the other terminals71). IGFET stands for _______. Insulated Gate Field Effect Transistor Independent Gate Field Efficiency Transistor Insight Gate Field Efficiency Transistor Insulated Gate Field Effective Transistor HintGate is insulated in MOSFET72). On what basis MOSFET characteristics depend on? Depletion type Enhancement type a & b Can’t say HintVarious modes of operation73). What are the benefits of short channel in LDMOSFETs? Low Resistance Tolerate high currents Tolerate high voltage All as mentioned earlier HintPower-related applications74). VMOSFETs has _______ connections of source. One Two Three Four HintTwo connections of Source75). When a MOSFET (n-channel) operates in First Quadrant? Positive voltage at Drain Negative voltage at Drain Positive voltage at Source Positive voltage at Gate HintPositive Voltage application at terminal drainMOSFET MCQs for Exams76). MOS Technology is based on _____. SRAM DRAM ROM EPROM HintDRAM77). While the study of Characteristics of MOSFET what is found? MOS capacitor MOS Transistor MOS resistor MOS Memory HintMOS Capacitors78). What are used in the production of Reprogrammable ROM? FGMOS PMOS NMOS CMOS HintFGMOS79). FGMOS stands for ________. Fluctuation-Gate MOSFET Floating-Gate MOSFET Functional-Gate MOSFET Floating-Gunn MOSFET HintFloating cells of memory80). What type of memories are designed using FGMOS? Flash Memory ROM EPROM All as mentioned earlier HintNVM technologies81). What happens to MOSFET when the flow of current is absent at terminal Gate? Voltage Controlled Resistor Current Controlled Resistor Voltage Controlled Capacitor Current Controlled Capacitor HintVoltage Controlled Resistor82). What works as Conducting channel in MOSFET? Physical layer Transmission layer Inversion layer Data insufficient HintInversion layer functions as a conducting channel83). With p variant substrate what does Inversion charge consists of? Electrons Holes Protons Neutrons HintP-substrate (n-channel device)84). Depletion region & substrate (neutral) are isolated by? AC Conditions DC Conditions Gate voltage Zero voltage HintIsolation among the fabricated devices over the similar substrate85). GCA stands for _______. Gradual Channel Approximation Gradual Component Approximation Gratitude Channel Allocation Gradual Channel Allocation HintSemi-analytical and the Analytical models86). GCA of MOSFETs is acceptable for? Short-channel Long-channel a & b Moderate-channel HintLarge aspect ratio87). How the capacitor gets charged in the MOSFET circuit of Switching? Applied VGS Applied VDS Applied Positive Voltage Applied Negative Voltage HintApplied VGS controls IDS88). When is Power handling capacity limited? MOSFET On MOSFET Off MOSFET On & Off Can’t say HintMOSFET is turned ON89). What classifies the mode in MOSFETs? Applied Voltage Capacitor connected P & N channels Resistor connected HintBased on the channels90). Can a Microcontroller drive MOSFET (p-channel)? Yes No Impossible Can’t say HintDriving devices with higher currents91). What does the arrow on MOSFETs symbol indicate? Electron direction Voltage polarity Variant of MOSFET Conventional flow of current HintThe electron's direction can be described92). Chopper circuits prefer _________. BJT UJT Diode MOSFET HintMOSFETs93). Which is considered as the basic block of Digital Electronics? Diode Resistor Capacitor MOSFET Hint‘Modern Digital Electronics’94). What can be the disadvantages of a MOSFET? Damage due to Static charge Unstable (Overload voltages) a & b High impedance at input HintStatic charges can destroy MOSFET95). The speed of switching in MOSFET is _____. Low High Moderate Can’t say HintHigh speed of switching96). What are important aspects of using a MOSFET? Great efficiency Can operate at low voltages High impedance at input All as mentioned earlier HintHigh impedance at input and efficiency to operate with the low amount of voltages97). What is preferred for the regulation of DC Motors? BJT UJT MESFET Power MOSFET HintPower MOSFET is used in the regulation98). Which amplifiers are preferred during Radio frequency applications? FET UJT MESFET MOSFET HintMOSFET amplifiers99). CMOS stands for ___________. Complementary Metal Oxide Semiconductor Commutative Metal Oxide Semiconductor Cosmopolitan MOS Customize MOS HintPMOS & NMOS FET combination100). What is BiCMOS? Combination of PMOS & NMOS Combination of BJT & JFET Combination of BJT & CMOS Combination of BJT & UJT HintA single IC accommodates BJT and CMOS Time is Up! Time's up
