Question

What is the ratio of critical frequency for reflection of radiowaves from $E,F_1$ and $F_2$ layers in ionosphere of earth's atmosphere having electron density $2\times 10^{11}$, $5\times 10^{11}$ and $8\times 10^{11}{m}^{-3}$ respectively?

• A. 6 : 12 : 9 : 33 : 10 : 11
• B. 1.41 : 2.13 : 3.18
• C. 1.41 : 2.24 : 2.83
• D. None of these

Answer 1

Answer: (C)

We know that $V_c=(\mathrm{Nmax}{)}^{1/2}$
$\therefore y_c\propto (\mathrm{Nmax}{)}^{1/2}$
$V_{cE}:V_{cF1}:V_{cF2}={\left(2\times 10^{11}\right)}^{1/2}:{\left(5\times 10^{11}\right)}^{1/2}:{\left(8\times 10^{11}\right)}^{12}$
$=1.41:2.24:2.83$