Question

For sky wave propagation of a $10MHz$ signal, what should be the maximum electron density in ionosphere?

• A. $\sim 1.2\times {10}^{12}{m}^{-3}$
• B. $\sim {10}^6{m}^{-3}$
• C. $\sim {10}^{14}{m}^{-3}$
• D. $\sim {10}^{22}{m}^{-3}$

Answer 1

The correct option is A $\sim 1.2\times {10}^{12}{m}^{-3}$

If maximum electron density of the ionosphere is $N_{max}$ / $m^3$, then the critical frequency $f_c$ is given by:

$f_c=9{\left(N_{max}\right)}^{\frac{1}{2}}$

$⟹10\times {10}^6=9{\left(N\right)}^{\frac{1}{2}}$

$⟹N=1.2\times {10}^{12}{m}^{-3}$