Question

What is the value of frequency at which an e.m wave must be propagated for the D-region of atmosphere to have a refractive index of 0.49? Electron density for D-region is 10⁹ m^-3:

Options

• 3.27 × 10⁵ Hz

• 3.22 × 10⁵ Hz

• 3.24 × 10⁵ Hz

• 3.26 × 10⁵ Hz

Answer 1

3.27 × 10⁵ Hz

Explanation:

`mu = sqrt(1 - (81.45 " N")/"V"^2)`

`0.49 = sqrt(1 - (81.45 xx 10^9)/"V"^2)`

`0.24 = 1 - (81.45 xx 10^9)/"V"^2`

V = `(81.45 xx 10^9)^(1//2)/1.24`

= 3.27 × 10⁵ Hz