Electronics Devices And Circuit 1(TTA)

25 Questions | Total Attempts: 451

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Electronics Devices And Circuit 1(TTA)

INSTRUCTIONS-1. NUMBER OF QUESTIONS 252. HAS A TIME LIMIT OF 15 MINUTES3. HAS A PASS MARKS OF 30%4. QUESTIONS PER PAGE 15. EACH QUESTIONS HAS 1 MARKS6. NEGATIVE MARKING FOR EACH QUESTIONS IS 0. 257. WILL ALLOW TO YOU GO BACK ,SKIP AND CHANGE YOUR ANSWERS8. WILL ALLOW TO YOU PRINT OUT YOUR RESULT AND CERTIFICATE 9. WILL ALLOW TO YOU PRINT OUT YOURS RESPONSE SHEET WITH CORRECT ANSWER KEY AND EXPLANATION.


Questions and Answers
  • 1. 
    .A long specimen of p-type semiconductor material:
    • A. 

      Is positively charged

    • B. 

      Is electrically neutral

    • C. 

      Has an electric filed directed along its length

    • D. 

      None of the above

  • 2. 
    N-type semiconductors are:
    • A. 

      Negatively charged

    • B. 

      Produced when Indium is added as an impurity to Germanium

    • C. 

      Produced when Phosphorous is added as an impurity to Silicon

    • D. 

      None of the above

  • 3. 
    The probability that an electron in a metal occupies the Fermi-level, at any temperature (>0 K) is:
    • A. 

      0

    • B. 

      1

    • C. 

      0.5

    • D. 

      None of the above None of the above none of these

  • 4. 
    .Measurement of Hall coefficient enables the determination of:
    • A. 

      Mobility of charge carriers

    • B. 

      Type of conductivity and concentration of charge carriers

    • C. 

      Temperature coefficient and thermal conductivity

    • D. 

      None of these

  • 5. 
    If the energy gap of a semiconductor is 1.1 e V it would be:
    • A. 

      Opaque to the visible light

    • B. 

      Transparent to the visible light

    • C. 

      Transparent to the ultraviolet radiation

    • D. 

      None of the above

  • 6. 
    In an intrinsic semiconductor, the mobility of electrons in the conduction band is:
    • A. 

      Less than the mobility of holes in the valence band

    • B. 

      Zero

    • C. 

      Greater than the mobility of holes in the valence band

    • D. 

      None of the above

  • 7. 
    The Hall Effect voltage in intrinsic silicon is:
    • A. 

      Positive

    • B. 

      Zero

    • C. 

      Negative

    • D. 

      None of the above

  • 8. 
    The Hall coefficient of an intrinsic semiconductor is
    • A. 

      Positive under all conditions

    • B. 

      Negative under all conditions

    • C. 

      Zero under all conditions

    • D. 

      None of the above

  • 9. 
    The electron and hole concentrations in a intrinsic semiconductor are ni and pi respectively. When doped with a p-type material, these change to n and p, respectively. Then
    • A. 

      n + p = ni + pi

    • B. 

      n + ni = p + pi

    • C. 

      np = nipi

    • D. 

      None of the above

  • 10. 
    If the temperature of an extrinsic semiconductor is increased so that the intrinsic carrier concentration is doubled, then
    • A. 

      The majority carrier density doubles

    • B. 

      The minority carrier density doubles

    • C. 

      Both majority and minority carrier densities double

    • D. 

      None of the above

  • 11. 
    At room temperature, the current in an intrinsic semiconductor is due to
    • A. 

      Holes

    • B. 

      Electrons

    • C. 

      Holes and electrons

    • D. 

      None of the above

  • 12. 
    Measurement of Hall coefficient in a semiconductor provides information on the
    • A. 

      Sign and mass of charge carriers

    • B. 

      Mass and concentration of charge carriers

    • C. 

      Sign of charge carriers alone

    • D. 

      Sign and concentration of charge carriers

  • 13. 
    .In a p-n junction diode: identify the false statement
    • A. 

      The depletion capacitance increases with increase in the reverse-bias

    • B. 

      The depletion capacitance decreases with increase in the reverse-bias

    • C. 

      The diffusion capacitance increases with increase in the forward-bias

    • D. 

      The diffusion capacitance is much higher than the depletion capacitance when it is forward-biased

  • 14. 
    The width of the depletion region is
    • A. 

      None of the above none of these

    • B. 

      Directly proportional to doping

    • C. 

      Inversely proportional to doping

    • D. 

      Independent of doping

  • 15. 
    The Fermi energy in p-n junction at thermal equilibrium is
    • A. 

      Proportional to distance

    • B. 

      Directly increases with the temperature

    • C. 

      Invariant with respect to distance

    • D. 

      None of the above

  • 16. 
    Gold is often diffused into silicon p-n junction devices to
    • A. 

      Is proportional to the square of the recombination rate

    • B. 

      Is proportional to the cube of the recombination rate

    • C. 

      Make silicon a direct gap semiconductor

    • D. 

      None of the above

  • 17. 
     18.In a forward-biased photo diode with increase in incident light intensity, the diode current
    • A. 

      Increases

    • B. 

      Remains constant

    • C. 

      Decreases

    • D. 

      None of the above

  • 18. 
    The Varactor diode is
    • A. 

      Voltage-dependent resistance

    • B. 

      Voltage-dependent capacitance

    • C. 

      Voltage-dependent inductor

    • D. 

      None of the above

  • 19. 
    The electric field in abrupt p-n junction is
    • A. 

      Linear function of distance

    • B. 

      Parabolic function of distance

    • C. 

      Independent of distance

    • D. 

      None of the above NONE OF THESE

  • 20. 
    A p-n junction, which is produced by  recrystallization on a base crystal, from a liquid phase of one or more components and the semiconductor is called
    • A. 

      Doped junction

    • B. 

      Alloy junction

    • C. 

      Fused junction

    • D. 

      None of the above

  • 21. 
    .Each diode of full wave  center-taped rectifier conducts for
    • A. 

      450 only

    • B. 

      1800 only

    • C. 

      3600 complete period

    • D. 

      2700 only

  • 22. 
    .Bulk resistance of a diode is
    • A. 

      The sum of resistance values of n-material and p-material

    • B. 

      The sum of half the resistance value of n-material and p-material

    • C. 

      Equivalent resistance of the resistance value of p- and n-material is parallel

    • D. 

      None of the above

  • 23. 
    .In a diode circuit, the point where the diode starts conducting is known as
    • A. 

      Cut-in point

    • B. 

      Cut-out point

    • C. 

      Knee point

    • D. 

      Cut-off point

  • 24. 
    A Zener diode should hav
    • A. 

      Heavily doped p- and n-regions

    • B. 

      Lightly doped p- and n-regions

    • C. 

      Narrow depletion region

    • D. 

      Both Heavily doped p- and n-regions AND Narrow depletion region

  • 25. 
    When a diode is forward-biased, the recombination of free electron and holes may produce
    • A. 

      Heat

    • B. 

      LighT

    • C. 

      Radiation

    • D. 

      All of the above

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