For sky wave propagation of a 10 MHz signal, which of the following statements are true:

Options

A. The minimum electron density in the ionosphere is `1.2xx10^(12)m^(-3)`
B. The minimum electron density in the ionosphere is `10^(6) m^(-3)`
C. The reflection of the given sky wave signal takes place from E layer of ionosphere
D. The reflection of the layer of ionosphere

Explanation

Here, v=10MHz =`10^(7) Hz. N=?`
`v=9sqrt(N)` or `10^(7)=9sqrt(N)`
Squaring both sides, `10^(14)=81xxN`
`N-(10^(14))/(81)=~1.2xx10^(12) m^(-3)`
The 10 MHz signal is reflected from F-layer of ionosphere.