An EM wave radiates outwards from a dipole antenna, with E0, as the amplitude of its electric field vector. The electric field E0, which transports significant energy from the source falls off as:

1. \(\frac{1}{r^3}\)

2. \(\frac{1}{r^2}\)

3. \(\frac{1}{r}\)

4. remains constant

(c)
Hint: The magnitude of the electric field depends on the distance from the source.
Step 1: Find the dependence of the electric field on the distance.
From a diode antenna, the electromagnetic waves are radiated outwards. The amplitude of electric field vector (E0) which transports significant energy from the source falls off inversely as the distance(r) from the antenna, i.e., E01r.