What term describes the bending of electromagnetic waves due to density changes in the medium?

What term describes the bending of electromagnetic waves due to density changes in the medium?

• A. Refraction
• B. Inversion
• C. Polarization
• D. Multipathing

Answer: (A)

Refraction is the bending of electromagnetic waves when they pass into a medium with a different density (and thus a different refractive index). When the wave enters at an angle, the change in speed causes the wavefronts to tilt, making the ray bend. Snell’s law describes how the angles relate to the speeds in the two media, which is why the path curves rather than continuing straight. In the atmosphere, density (and refractive index) changes with height, so radar waves bend as they travel through air layers. The other terms don’t describe this bending: inversion refers to temperature or density layering that can trap or lens waves, polarization is about the orientation of the electric field, and multipathing describes multiple possible paths (often from reflections or complex refraction) rather than the basic bend due to a single density change.

Refraction is the bending of electromagnetic waves when they pass into a medium with a different density (and thus a different refractive index). When the wave enters at an angle, the change in speed causes the wavefronts to tilt, making the ray bend. Snell’s law describes how the angles relate to the speeds in the two media, which is why the path curves rather than continuing straight. In the atmosphere, density (and refractive index) changes with height, so radar waves bend as they travel through air layers. The other terms don’t describe this bending: inversion refers to temperature or density layering that can trap or lens waves, polarization is about the orientation of the electric field, and multipathing describes multiple possible paths (often from reflections or complex refraction) rather than the basic bend due to a single density change.