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Question 20279
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Principles of Communication: Optical Fibre MCQ

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Optical FibreMediumQuestion 20279

Question

Modal dispersion in optical fibres causes:
  1. A
    Signal amplification
  2. B
    Pulse broadening, limiting bandwidth
    Correct
  3. C
    Noise reduction
  4. D
    Increased transmission speed

Correct answer

Pulse broadening, limiting bandwidth

Explanation

In multimode fibre, different modes (ray angles) travel at slightly different speeds → pulses broaden → intersymbol interference (ISI) limits bit rate. Single-mode fibre (core diameter ≈ 8–10 μm) eliminates modal dispersion; only chromatic dispersion remains.

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