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InsemMar 20252019 patternBE E&TC

Fiber Optic Communication (FOC) SPPU Insem Question Paper Mar 2025

All 4 questions from this SPPU insem paper, as printed. Read them here or open the PDF.

Open the PDFMost repeated FOC questions
Subject code
404190
Pattern
2019 pattern
Exam
Insem
Session
Mar 2025
Max. marks
30
Time
1 Hour
Semester
VIII
Paper code
[6411]-60

Printed for: B.E. (Electronics & Telecomunication Engineering) (Insem.)

Instructions to the candidates

  1. Answer Q. 1 or Q. 2, Q. 3 or Q. 4.
  2. Neat diagrams must be drawn wherever necessary.
  3. Figures to the right indicate full marks.
  4. Assume suitable data, if necessary.

Questions

  1. Q1

    1. a)

      Describe the following terms i) Total internal reflection ii) Acceptance angle iii) Numerical aperture

      [5]
    2. b)

      Compare SMSI,MMSI and MMGI fibers.

      [4]
    3. c)

      A step index fiber has a relative refractive index difference of 1.3% & a core refractive index of 1.5. The core diameter is 100  m and operating wavelength is 850nm. Assuming fiber is kept in air, calculate Numerical aperture of fiber, acceptance angle and critical angle.

      Also asked:Mar 2024

      [6]

  2. Q2

    1. a)

      Draw and explain optical fiber communication system showing all the key elements. Enlist the advantages of optical fibers as a communication media.

      Also asked:Mar 2024

      [5]
    2. b)

      Enlist losses in optical fiber and explain any three

      [4]
    3. c)

      A multimode graded index fiber exhibits total pulse broadening of 0.1  sec over a distance of 15km. Calculate i) Maximum possible bandwidth on the link ii) The pulse dispersion per unit length iii) The bandwidth-length product for the fiber 2

      Also asked:Mar 2024

      [6]

  3. Q3

    1. a)

      Distinguish direct and indirect band- gap semiconductor materials. Also state the major requirements of good optical sources.

      Also asked:Mar 2024

      [6]
    2. b)

      Explain the following terms w.r.t. LED i) Spectral Width ii) Modulation Bandwidth iii) I-P characteristics

      [6]
    3. c)

      Calculate the emission wavelength in nm of the light emitted using a semiconductor material with energy band-gap of 3eV.

      Also asked:Mar 2024

      [3]

  4. Q4

    1. a)

      Differentiate stimulated emission and spontaneous emission.

      [5]
    2. b)

      A double heterojunction InGAsP LED emitting at a peak wavelength of 1310 nm has radiative and non- radiative recombination times of 30 ns and 100 ns respectively. The drive current is 40 mA. Determine i) Bulk recombination lifetime ii) The internal quantum efficiency iii) Internal Power level

      Also asked:Mar 2024

      [6]
    3. c)

      What do you understand about the term external quantum efficiency and internal quantum efficiency in the case of LED? ♦♦♦

      [4]