Question

In short wave communication wave of which of the following frequencies will be reflected back by the ionosphere layer having electron density 1.23 × 10¹² m

(A) 2 MHz 

(B) 10 MHz 

(C) 12 MHz 

(D) 18 MHz

Answer 1

The correct option is (B) 10 MHz.

Explanation:

f_c = 9√(N_max)

Given: electron density = N_max = 1.23 × 10¹² m

 ∴ f_c = 9√(1.23 × 10¹²)

f_c ≈ 10MHz