MCQ in Solid State Devices Part 12 | ECE Board Exam

(Last Updated On: August 9, 2018)

This is the Multiples Choice Questions Part 12 of the Series in Solid State Devices/Circuits as one of the Electronics Engineering topic. In Preparation for the ECE Board Exam make sure to expose yourself and familiarize in each and every questions compiled here taken from various sources including but not limited to past Board Exam Questions in Electronics Engineering field, Electronics Books, Journals and other Electronics References.

MCQ Topic Outline included in ECE Board Exam Syllabi

• MCQs in Semiconductor Fundamentals
• MCQs in Transistor Components
• MCQs in Circuit Analysis and Design
• MCQs in Special Services (Photo Electric, Photo voltaic)

Continue Practice Exam Test Questions Part 12 of the Series

Choose the letter of the best answer in each questions.

551. In order to increase further the input resistance of a FET, its gate is insulated. An example of this type is the

A. fieldistor

B. JFET

C. MOS-FET

D. A and B above

552. What is the insulator used in most MOS-FET?

A. CO2

B. SiO2

C. mica

D. plastic

553. An n-channel JFET has a drain-source saturation current IDSS = 10 mA and a gate-source pinch-off voltage Vp = -4 V. If the applied reverse gate-source voltage VGS = 2 V, calculate the drain current ID.

A. 2.5 mA

B. 5.0 mA

C. 10.0 mA

D. 22.5 mA

554. Base from Shockley’s equation of a JFET, what is the drain current when the applied voltage VGS is exactly equal to the pinch-off voltage Vp?

A. IDSS

B. maximum

C. minimum

D. zero

255. The transconductance of a JFET is defined as

A. dID/dVGS

B. dVGS/dID

C. dIDSS/dVGS

D. dID/dVp

556. A field-effect transistor in which the gate electrode is not a pn junction (as in the junction field-effect transistor) but a thin metal film insulated from the semiconductor channel by a thin oxide film.

A. MOSFET (enhancement type)

B. MOSFET (depletion type)

C. IGFET

D. all of the above

557. In MOSFET, it is the foundation upon which the device will be constructed and is formed from a silicon base

A. substrate

B. slab

C. source

D. base

558. A type of MOSFET wherein originally there is no channel between the drain and the source

A. depletion type

B. enhancement type

C. break type

D. insulated type

559. What type of MOSFET whose channel is originally thick but narrows as the proper gate bias is applied?

A. enhancement

B. depletion

C. transverse

D. all of the above

560. The amount of voltage needed at the gate-source terminal for an enhancement type MOSFET so that a channel can be formed for the current to flow.

A. “ON” voltage

B. pinch-off voltage

C. threshold voltage

D. trigger voltage

561. To switch off the depletion type MOSFET, the channel should be depleted. Depletion of the channel is done by applying enough voltage across the gate-source terminal. What do you call this voltage?

A. pinch-off voltage

B. trigger voltage

C. holding voltage

D. threshold voltage

562. The substrate of a MOSFET is usually connected internally to

A. source

B. gate

C. drain

D. channel

563.In an n-channel enhancement type MOSFET, the gate voltage should be ________ with respect to the source in order to produce or enhance a channel.

A. the same

B. positive

C. negative

D. either positive or negative

564. To deplete a channel from a p-channel IGFET depletion type, the gate voltage should be ________ with respect to the source.

A. the same

B. positive

C. negative

D. either positive or negative as long as it is greater

565. The substrate used in a p-channel IGFET enhancement type

A. n -type material

B. n+ -type material

C. p -type material

D. p+ -type material

566. The base material of a MOSFET which extends as an additional terminal

A. source (S)

B. channel (C)

C. drain (D)

D. substrate (SS)

567. Which FET that has a substrate?

A. MOSFET enhancement type

B. IGFET

C. MOSFET depletion type

D. all of the above

568. What is the difference between a JFET and a MOSFET?

A. The gate of a MOSFET is insulated.

B. MOSFET uses a substrate in its construction.

C. MOSFET can work in both forward and reverse gate-source voltages.

D. all of the above

569. Calculate the transconductance of a p-channel MOSFET enhancement type if the gate-source voltage VGS = -8 V, threshold voltage VT = -4 and a constant k = 0.3 mA/V2.

A. 1.2 mS

B. 2.4 mS

C. 3.6 mS

D. 7.2 mS

570. One drawback of JFET devices is the strong dependence of the devices’ parameters on the channel geometry. Which parameter is an example of this?

A. drain saturation current (IDSS)

B. pinch-off voltage (VP)

C. transconductance (gm)

D. all of the above

571. JFET cutoff frequency is dependent on channel length by a factor of

A. 1/L

B. 1/L2

C. 1/L3

D. 1/L4

572. Which FET operates as close as BJT in terms of switching?

A. JFET

B. MOSFET depletion type

C. MOSFET enhancement type

D. IGFET

573. Generally, MOSFET has low power handling capability than BJT. To increase MOSFET power, the channel should be made

A. narrow and long

B. narrow and short

C. wide and long

D. wide and short

574. Which FET has a wide and short effective channel?

A. JFET

B. MOSFET

C. IGFET

D. V-MOSFET

575. A type of FET wherein the channel is formed in the vertical direction rather than horizontal

A. JFET

B. MOSFET

C. IGFET

D. V-MOSFET

576. Advantage or advantages of V-MOS over BJT

A. No stored charge and therefore faster in switching action.

B. A negative temperature dependence of output current which eliminates thermal runaway.

C. High input impedance and therefore high current gain.

D. all of the above

577. In general, which of the transistors is particularly more useful in integrated-circuit (IC) chips?

A. BJTs

B. FETs

C. UJTs

D. all of the above

578. A monolithic semiconductor-amplifying device in which a high-impedance GATE electrode controls the flow of current carriers through a thin bar of semiconductor called the CHANNEL. Ohmic connections made to the ends of the channel constitute SOURCE and DRAIN electrodes.

A. BJT

B. UJT

C. FET

D. UPT

579. A junction field effect transistor has a drain saturation current of 10 mA and a pinch-off voltage of -4 V. Calculate the maximum transconductance.

A. 2.5 mS

B. 5.0 mS

C. 25.0 mS

D. 50.0 mS

580. In semiconductor application, which of the following statement is not true?

A. An ohmmeter test across the base-collector terminal of a transistor should show low resistance in one polarity and high resistance in the opposite polarity.

B. A triac is a bidirectional device.

C. An ohmmeter test across a diode shows low resistance in one polarity and high resistance in the opposite polarity.

D. An ohmmeter test across the base-collector of a transistor should show low resistance for both polarities.

ANSWER: D

Questions and Answers in Solid State Devices

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Complete List of MCQ in Electronics Engineering per topic