North Carolina RADAR State Practice Exam

What happens to the energy transmitted by an antenna if it is not absorbed, reflected, or refracted?

1. It dissipates quickly

2. It travels indefinitely

3. It reduces in intensity

4. It changes frequency

The correct answer is: It travels indefinitely

The energy transmitted by an antenna, assuming it is not absorbed, reflected, or refracted, travels indefinitely through space. This characteristic is primarily due to the nature of electromagnetic waves, which can propagate over long distances without any medium to interfere with their movement. In the absence of interactions like absorption or reflection, the energy maintains its original form and continues to travel away from the antenna. While in practice, factors such as atmospheric conditions, obstacles, and distance can cause the energy to diminish in strength over time, the theoretical understanding is that in the vacuum of space, electromagnetic energy would keep moving indefinitely unless acted upon by some external forces. This concept aligns with the principles of wave propagation and helps explain how radio signals can transmit over vast distances.