An EM wave radiation outwards from a dipole antenna with $E_0$ as the amplitude of its electric field vector . The electric field $E_0$ which transports significant energy from the source falls off as

Question

$\begin{array}{1 1} \large\frac{1}{r^3} \\\large\frac{1}{r^2} \\ \large\frac{1}{8} \\ remains\;constant \end{array} $

Answer 1

Solution :

From a diode antenna , the $e_m$ waves are radiated outwards .

The amplitude of the electric field vector $(E_0)$ transports significant energy from the source .

But this varies inversely as the distance (r) from the antenm.

Hence $E_0 \alpha \large\frac{1}{r}$