The maximum frequency for reflection of sky waves from a certain layer of the ionosphere is found to be f_max= 9(N_max)^1/2, where N_maxis the maximum electron density at that layer of the ionosphere.
On a certain day it is observed that signals of frequencies higher than 5 MHz are not received by reflection from the F₁ layer of the ionosphere while signals of frequencies higher than 8 MHz are not received by reflection from the F₂ layer of the ionosphere. Estimate the maximum electron densities of the F₁ and F₂ layers on that day.

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Alok Kumar Singh | Contributor-Level 10

10 months ago

This is a Short Answer Type Questions as classified in NCERT Exemplar

Frequency, fmax= 9 (N_max)^1/2

For F1 layer frequency is 5MHz

So 5 $* 10^{6} = 9 (N m a x)$ ^1/2

Nmax= (5/9 $* 10^{6}$ )²= 3.086 $*$ 10¹¹/m³

For F2 layer 8MHz

8 $* 10^{6} = 9 (N m a x)$ ^1/2

Nmax= (8/9 $* 10^{6}$ )²= 7.9 $*$ 10¹¹/m³

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