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220-801 · Question #270

Which of the following is a characteristic of single-mode fiber compared to multi-mode?

The correct answer is B. Single-mode fiber uses laser while multi-mode does not. Single-mode fiber (SMF) uses a laser (coherent, narrow-wavelength light) as its light source, which allows the light to travel in a single straight path (mode) through the very small core (~9 microns). This enables extremely long transmission distances (many kilometers)…

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Question

Which of the following is a characteristic of single-mode fiber compared to multi-mode?

Options

  • AMulti-mode fiber is resistant to EMI while single mode is not.
  • BSingle-mode fiber uses laser while multi-mode does not.
  • CMulti-mode fiber supports lower speeds than single-mode.
  • DSingle-mode fiber uses light, while multi-mode can use light or RF.

How the community answered

(28 responses)
  • A
    7% (2)
  • B
    89% (25)
  • D
    4% (1)

Explanation

Single-mode fiber (SMF) uses a laser (coherent, narrow-wavelength light) as its light source, which allows the light to travel in a single straight path (mode) through the very small core (~9 microns). This enables extremely long transmission distances (many kilometers). Multi-mode fiber (MMF) uses LEDs, which emit light across multiple wavelengths and angles, causing modal dispersion and limiting distance. Both fiber types are immune to EMI (ruling out A). Both support high speeds - SMF actually supports higher speeds over longer distances (ruling out C). Neither uses RF - that is wireless/coax technology (ruling out D).

Topics

#single-mode fiber#multi-mode fiber#fiber optics#laser transmission

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