Question

Communication on ground is through electromagnetic waves of wavelength

• A. Larger than $600m$
• B. Between $200$ and $600m$
• C. Between $1$ and $5m$
• D. Between ${10}^{-13}$ and $0.1m$

Answer 1

Answer: (D)

Between ${10}^{-13}$ and $0.1m$

The required wavelength should be from ${10}^{-3}m$ to $0.1m$
$\Rightarrow$ $I_e=\frac{100}{90}\times 10mA=11.1mA$