What is the primary function of an antenna?

The primary function of an antenna is to radiate and/or collect electromagnetic waves. Antennas are designed to convert electrical energy into electromagnetic waves for transmission and vice versa for reception. When an alternating current flows through the antenna, it creates an oscillating electric field, which in turn generates an oscillating magnetic field, resulting in the radiation of electromagnetic waves into space. Conversely, when electromagnetic waves strike the antenna, it induces a small alternating current within the antenna, allowing for the collection of signals.

This function is crucial in various applications, including communication systems, radio, television broadcasting, and radar systems. Antennas come in various shapes and sizes, suited for different frequencies and applications, but their core purpose remains the efficient transfer of energy in the form of electromagnetic radiation. Hence, the correct answer reflects the fundamental role antennas play in electromagnetic wave propagation and reception.