Practicing Success

Target Exam

CUET

Subject

Physics

Chapter

Electromagnetic Waves

Question:

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:

Options:

$\frac{1}{r^3}$

$\frac{1}{r^2}$

$\frac{1}{r}$

remains constant

Correct Answer:

$\frac{1}{r}$

Explanation:

From a dipole 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., $E_0 \propto \frac{1}{r}$.