Question

In short wave communication waves of which of the following frequencies will be reflected back by the ionospheric layer, having electron density 10¹¹ per m³

• A. 2 MHz
• B. 10 MHz
• C. 12 MHz
• D. 18 MHz

Answer 1

Answer: (A)

2 MHz

Answer 2

By using $f_{c} \approx 9({N1/2}_{\max}$⇒ $f_{c} \approx 2MHz$