Question

The electron density of E, $F_1$ , $F_2$ layers of ionosphere is 2 $\times {10}^{11}$, 5 $\times {10}^{11}$ and 8 $\times {10}^{11}$ $m^{-3}$ respectively. What is the ratio of critical frequency for reflection of radiowaves

• A. 2 : 4 : 3
• B. 4 : 3 : 2
• C. 2 : 3 : 4
• D. 3 : 2 : 4

Answer 1

The correct option is C 2 : 3 : 4

$f_c\alpha {\left(N\right)}^{\frac{1}{2}}\Rightarrow (f_c{)}_E:(f_c{)}_{f_1}:(f_c{)}_{F_2}$
= ${(2\times {10}^{11})}^{\frac{1}{2}}:{(5\times {10}^{11})}^{\frac{1}{2}}:{(8\times {10}^{11})}^{\frac{1}{2}}$ = 2: 3 :4