Question

Refractive index of ionosphere is

• A. zero
• B. more than one
• C. less than one
• D. one

Answer 1

Answer: (C)

less than one

Answer 2

The refractive index of ionosphere is $\mu = \sqrt{ 1 - \frac{ 80.6 \, N }{ f^2 }}$ where N is free electron density typically equal to $10^{11} \, m^{ - 3 }$ and v is frequency of waves in kHz. So, we have $\mu < 1$ Hence, refractive index of ionosphere is less than one.