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What is the value of frequency at which electromagnetic wave must be propagated for the D-region of atmosphere to have a refractive index of 0 . 5 ? Electron density for D-region is 400 electrons/cc

Options

  1. A200   kHz
  2. B104.2 kHz
  3. C208.4 kHz
  4. D312.6 kHz

Correct answer

C. 208.4 kHz

Step-by-step solution

Here, N = 400 electrons c/cc = 400 × 10 6 electrons m - 3 μ = 0.5 = 1 - 81.56 N v 2 = 1 - 81.56 × 400 × 10 6 v 2 On solving, v = 208.4 kHz.

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