Semiconductor Physics And Electronic Devices

20 Questions | Total Attempts: 122

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Semiconductor Quizzes & Trivia

Questions and Answers
  • 1. 
    Is operating temperature range of ICs, computers and other semiconductor devices conditioned by the used semiconductor material's band gap?
    • A. 

      Yes, the more the band gap, the more temperature range

    • B. 

      No, as concentration of minority charge carriers is independent from temperature

    • C. 

      Conditioned partially as by increasing the temperature, carriers' mobility decreases

    • D. 

      No, as band gap does not depend on temperature

    • E. 

      The correct answer is missing

  • 2. 
    Which expression is wrong?
    • A. 

      Diode subtypes are: point-junction diodes, stabilitrons, varicaps and tunnel diodes

    • B. 

      In tunnel diodes reverse current for the same voltage is higher than direct current value

    • C. 

      In varicaps with increase of voltage barrier capacitance increases

    • D. 

      Schottky diodes operation is based on processes which take place in semiconductor-metal contact

    • E. 

      The response time of Schottky diodes, therefore, frequency properties are conditioned by barrier capacitance

  • 3. 
    Field effect transistors, compared with bipolar transistors
    • A. 

      Have small input resistance

    • B. 

      Have small noise coefficient

    • C. 

      The current is at the same time conditioned by electrons and holes

    • D. 

      Provide current amplification

    • E. 

      The performance is mainly conditioned by injection of minority carriers

  • 4. 
    Through which device is the electrical signal amplification implemented?
    • A. 

      Resistor

    • B. 

      Capacitor and inductor

    • C. 

      Diode

    • D. 

      Transistor

    • E. 

      Photodiode

  • 5. 
    How many pins does the field effect transistor have?
    • A. 

      1 gate

    • B. 

      2 sources and 1 drain

    • C. 

      3 sources, 1 gates and 1 drain

    • D. 

      2 bases and 1 collector

    • E. 

      1 source, 1 gate and 1 drain

  • 6. 
    Is the gate of a field effect transistor isolated from its channel?
    • A. 

      Yes

    • B. 

      No

    • C. 

      Partially and there is weak tunnel coupling

    • D. 

      In saturation mode of field effect transistor most part of channel current flows through gate

    • E. 

      The correct answer is missing

  • 7. 
    N – type Ge sample, which is anticipated for making a transistor, has 1.5 Ohm􀁷cm specific resistance and 5.4􀁷103 cm3/Kl Holy coefficient. What does the charge carriers' concentration and their mobility equal?
    • A. 

      1.6*10^21 m-3, 5 m2/V􀁷s

    • B. 

      1.6*10^21 m-3, 0.1 m2/V􀁷s

    • C. 

      1.16*10^21 m-3, 0.36 m2/V􀁷s

    • D. 

      2*10^20 m-3, 0.36 m2/V􀁷s

    • E. 

      The correct answer is missing.

  • 8. 
    By means of what semiconductor device can light influence be detected?
    • A. 

      Posistor

    • B. 

      Resistor

    • C. 

      Photodiode

    • D. 

      Capacitor

    • E. 

      Inductor

  • 9. 
    Which materials' conductivity is higher?
    • A. 

      Dielectrics

    • B. 

      Semiconductors

    • C. 

      Metals

    • D. 

      All have low conductivity

    • E. 

      All have high conductivity

  • 10. 
    How does the negative differential resistance current range change depending on the density of lightly degenerated n-region impurities in tunnel diode?
    • A. 

      Interval decreases when increasing density

    • B. 

      Interval increases when increasing density

    • C. 

      It is not conditioned by density of impurity

    • D. 

      Interval increases when reducing density

    • E. 

      All the conditions are true

  • 11. 
    Generally, what is the response time of photodiode conditioned by?
    • A. 

      The diffusion time of equilibrium carriers in the base

    • B. 

      Their transit time through the layer of p-n junction

    • C. 

      RC constant of diode structure

    • D. 

      Only A and C

    • E. 

      Conditions A, B, C

  • 12. 
    Which statement mentioned below is not true for ohmic contact?
    • A. 

      Electrical resistance of ohmic contact is small

    • B. 

      Electrical resistance of ohmic contact does not depend on the current direction if the current value does not exceed the given value

    • C. 

      Electrical resistance of ohmic contact does not depend on the current direction in case of any current value flowing through it

    • D. 

      Most part of ohmic contacts is formed on the basis of n-n+ or p-p+ type contacts

    • E. 

      All the answers are correct

  • 13. 
    By increasing the lifetime of electrons 4 times, their diffusion length
    • A. 

      Increases 4 times

    • B. 

      Increases twice

    • C. 

      Does not increase

    • D. 

      Reduces twice

    • E. 

      The correct answer is missing

  • 14. 
    What does the generation frequency depend on in Gunn diode?
    • A. 

      Mobility speed of field domain

    • B. 

      Impurity density in semiconductor

    • C. 

      Sample length

    • D. 

      Dielectric permeability of material

    • E. 

      All the answers are correct

  • 15. 
    How can the cutoff voltage of MOS transistor change?
    • A. 

      By opposite voltage of substrate-channel junction, when substrate is higher ohmic than the channel

    • B. 

      By opposite voltage of substrate-channel junction when substrate resistance is equal or smaller than the channel resistance

    • C. 

      By voltage applied to the gate

    • D. 

      By A and C

    • E. 

      By B and C

  • 16. 
    Which statement is wrong for unipolar transistors?
    • A. 

      In unipolar transistors, physical processes of current transport are conditioned by one sign carriers-electrons or holes

    • B. 

      In unipolar transistors, physical processes of current transport are conditioned by the injection of minority carriers.

    • C. 

      In unipolar transistors current control is carried out by the vertical electrical field

    • D. 

      The surface channel unipolar transistor includes metal-dielectric-semiconductor structure

    • E. 

      The correct answer is missing

  • 17. 
    What is the high frequency property of Schottky diode conditioned by?
    • A. 

      Moving the majority carriers through diode

    • B. 

      Excluding minority carriers’ accumulation in diode

    • C. 

      Value of Schottky barrier

    • D. 

      Impurity density in a semiconductor

    • E. 

      Only C and D

  • 18. 
    Which of the below written statements is wrong for an integrated capacitor?
    • A. 

      An integrated capacitor represents IC element consisting of conductive electrodes (plates), divided by isolation layer

    • B. 

      In ICs the role of an integrated capacitor is often performed by reverse-biased p-n junctions of a transistor structure

    • C. 

      The quality factor of an integrated capacitor is defined by the following: Q = 2 π f R Cwhere f −operating frequency, C − capacitance of a capacitor, R − resistance of a resistor sequentially connected with the transistor

    • D. 

      The quality factor of an integrated capacitor characterizes loss of power at capacitive current junction

    • E. 

      All the answers are correct

  • 19. 
    Which of the below mentioned statements is wrong for electronic lithography?
    • A. 

      In this method the electron beams are used as a source of radiation

    • B. 

      The method of electron beam lithography is based on non-thermal influence left by electron beam on resist

    • C. 

      The ultraviolet beams fall on resist surface at electron beam lithography

    • D. 

      It is possible to reduce diffraction effects by increasing the electron accelerating voltage in electron beam lithography

    • E. 

      The correct answer is missing

  • 20. 
    Which of the below mentioned statements is correct for a bipolar transistor in saturation mode?
    • A. 

      Emitter and collector junctions are forward-biased

    • B. 

      Emitter junction is forward-biased, and collector junction –reverse-biased

    • C. 

      Transistor base resistance in this mode is maximum, as emitter and collector junctions inject large number of free particles to base region

    • D. 

      Free carriers’ extraction takes place from transistor base being in this mode

    • E. 

      The correct answer is missing

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