If the critical frequency for sky wave propagation is 12 MHz , then the maximum electron density in the ionosphere is

Options

A. ` 1.78 xx 10^(12) m^(-3) `
B. ` 0.178 xx 10^(10) m^(-3)`
C. ` 1.12 xx 10^(12) m^(-3)`
D. `0.56 xx 10^(12) m^(-3)`

Answer

A

Explanation

Critical frequency for sky wave propagation ` f_(c)=9(N_("max"))^(1//2)`
`or N_("max")=(f_(c)^(2))/(81)=((12 xx 10^(6))^(2))/( 81)-1.78 xx 10^(12) m^(-3)`