logo

CuriousTab

CuriousTab

Discussion

Home ‣ Electronics and Communication Engineering ‣ Materials and Components See What Others Are Saying!
  • Question

  • The minority carrier life time and diffusion constant in a semiconducting material are 100 ?s and 100 cm2/s respectively. The diffusion length of carriers is


  • Options
  • A. 0.1 cm
  • B. 0.01 cm
  • C. 0.0141 cm
  • D. 1 cm

  • Correct Answer
  • 0.1 cm 

    Explanation
    Diffusion length = sqrt(Carrier life time x Diffusion constant) = (100 x 10-6 x 100)0.5 = 0.1 cm.

    More questions

    • 1. A radar has a maximum range of 120 km. The maximum allowable pulse repetition frequency for unambiguous reception is

    • Options
    • A. 1250
    • B. 330
    • C. 2500
    • D. 8330
      • Discuss
    • 2. An unmodulated voltage 10 V effective is applied to a dioxide detector in which load resistance is 4 x 10-5 ohms. A micrometer shows that the rectified DC current in this resistance is 30 A. The input resistance of the detector is

    • Options
    • A. 114 kW
    • B. 336 kW
    • C. 384 kW
    • D. 455 kW
      • Discuss
    • 3. For a BJT a = 0.98, then ? =

    • Options
    • A. 0.02
    • B. 0.5
    • C. 4.9
    • D. 48
      • Discuss
    • 4. If the temperature of an extrinsic semiconductor is increased so that the intrinsic carrier concentration is doubled, then

    • Options
    • A. the majority carrier density is doubled
    • B. the minority carrier density is doubled
    • C. the minority carrier density becomes 4 times the original value
    • D. both the majority and minority carrier densities double
      • Discuss
    • 5. A cycloconverter is

    • Options
    • A. ac-dc converter
    • B. dc-ac converter
    • C. dc-dc converter
    • D. ac-ac converter
      • Discuss
    • 6. Consider the following DO statement in Fortran 77

      DO 52 N = 1, 10, 3

      The number of DO loop executions in the above statement is

    • Options
    • A. 1
    • B. 10
    • C. 3
    • D. 4
      • Discuss
    • 7. In a single phase semiconverter feeding a highly inductive load, the load current is

    • Options
    • A. sinusoidal
    • B. nearly constant
    • C. absolutely constant
    • D. rectangular
      • Discuss
    • 8. If ton and toff are the turn on and turn off times of a thyristor, then

    • Options
    • A. ton and toff are almost equal
    • B. ton >> toff
    • C. toff >> ton
    • D. ton is about twice toff
      • Discuss
    • 9. Which inverter circuit uses coupled inductors?

    • Options
    • A. Modified McMurray full bridge inverter
    • B. McMurray Bedford half bridge inverter
    • C. Modified McMurray Bedford half bridge inverter
    • D. Both (b) and (c)
      • Discuss
    • 10. If there are no permanent dipoles in a dielectric material, the dielectric constant is independent of temperature.

    • Options
    • A. True
    • B. False
      • Discuss

    Comments

    There are no comments.
Enter a new Comment




Aptitude

Engineering

Programming

Reasoning

Links

Copyright ©CuriousTab. All rights reserved.