A layer of ionosphere does not reflect waves with frequencies greater than 10 MHz; then maximum electron density in this layer is
Answer & explanation
Correct answer: option 4
The correct answer is Option 4: 1.23 × 1012 m−3
The frequency of electromagnetic wave is
$\nu = 9\sqrt{\text{ maximum electron density}} = 9 \sqrt{d_{max}}$
$\Rightarrow d_{max} = \frac{\nu^2}{81} = \frac{100\times 10^{12}}{81} = 1.23\times 10^{12}$