Question

On a particular day, the maximum frequency reflected the ionosphere is 9MHz. On another day, it was found to increase by 1MHz. Calculate, the ratio of the maximum electron densities of the ionosphere on the two days

• A. 0.5
• B. 0.2
• C. 0.81
• D. 0.1

Answer 1

The correct option is C 0.81

The critical frequency is given by

$fc=9{\left(Nmax\right)}^{1/2}$

$Nmax:-$ max. electron density

$\frac{Case1}{Case2}\Rightarrow \frac{Nmax}{{Nmax}^1}={\left(\frac{fc}{{fc}^1}\right)}^2={\left(\frac{9}{10}\right)}^2=81:100$

$\Rightarrow 0.81$

$\Rightarrow$ Option (C) is the correct answer.