What phenomenon occurs when a radio antenna is placed close to a power line?

When a radio antenna is placed close to a power line, the phenomenon that occurs is interference. This happens because the electromagnetic fields generated by the power line can disrupt the normal reception of the radio signals by the antenna. The power line emits a variety of frequencies, which can mix with or overpower the desired radio signals. This creates unwanted noise and can degrade the clarity of the received signal.

Interference is particularly significant in urban areas where power lines are prevalent, as the combination of the power line signals and the radio waves can lead to distortion, which impacts the overall performance of the radio equipment.

Reflection, diffraction, and refraction are not as relevant in this context. Reflection involves the bouncing back of waves when they hit a barrier, diffraction refers to the bending of waves around obstacles, and refraction involves the change of direction of waves as they pass through different mediums. While these phenomena do occur in various scenarios involving radio waves, they do not directly describe the disruptive effects caused by proximity to power lines.