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Consider the following statements: (a) LASER diode generates monochromatic coherent light which reduces chromatic dispersion (b) LASER source is useful for high power long-distance optical communication (c) LASERs have longer lifetime than LEDs (d) LASER diodes are less temperature-sensitive than LEDs Which of the above statements are correct?

Consider the following statements: (a) LASER diode generates monochromatic coherent light which reduces chromatic dispersion (b) LASER source is useful for high power long-distance optical communication (c) LASERs have longer lifetime than LEDs (d) LASER diodes are less temperature-sensitive than LEDs Which of the above statements are correct? Correct Answer (a) and (b)

  • Monochromatic Dispersion results from the spectral width of the emitter i.e. the spectral width determines the number of different wavelengths that are emitted by the LED or laser.
  • One way to reduce chromatic dispersion is to narrow the spectral width.
  • A monochromatic laser emits only one wavelength & therefore reduces or does not contribute to chromatic dispersion.(Statement (a) is correct)
  • Lasers can produce high output power in fiber optic communications. The laser source is useful for high power i.e. more than 20 mW is available. (Statement (b) is correct)
  • LED’s have a longer life than lasers, i.e.

          LED’s: 105 - 108 hours

          Lasers: 105 hours(Statement (c) is wrong)

  • In terms of temperature effect, lasers are more temperature-sensitive than LED’s.(Statement (iv) is wrong)

Related Questions

The 2018 Nobel Prize in Physics has been awarded in laser physics for the optical tweezers and their applications to biological systems for the method of generating high-intensity, ultra-short optical pulses. Which of the following verifies the given statement? I:  The 2018 Nobel Prize in Physics has been awarded in laser physics for the optical tweezers. II: The 2018 Nobel Prize in Physics has been awarded for applications of the optical tweezers to biological systems. III: The 2018 Nobel Prize in Physics has been awarded for the method of generating high-intensity, ultra-short optical pulses using the optical tweezers.
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1. The wavelength of visible light is more than that of X-ray.
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3. The energy of UV light photons is less than that of visible light photons.
Which of the statement(s) given above is/are correct?
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1. Computer-mediated communication (CMC) is defined as any human communication that occurs through the use of two or more electronic devices.
2. Computer-mediated Communication can be broken down into two forms i.e. synchronous and asynchronous.
3. Synchronous computer mediated communication refers to communication which occurs in real time.
4. Asynchronous computer mediated communication refers to communication which takes place when the parties engaged are not communicating in unison.
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2. Communication is a learnt ability.
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4. Communication cannot break down.
5. More communication means more effective learning by students.
6. Value of what is learnt through classroom communication is not an issue for students.
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