Which term best describes the propagation phenomenon that spreads energy around edges and obstacles?

• A. Water in the Waveguide
• B. SERRATED RANGE RINGS
• C. Diffraction
• D. Power Line Effect

Answer: (C)

Diffraction is the way energy bends and spreads when a wavefront meets an obstacle or passes through an opening. In simple terms, every point on a wavefront acts like a tiny source of waves; when part of the wave is blocked by an edge, the unobstructed portions radiate around the edge and create new wavefronts that propagate into the region behind the obstacle. This lets energy appear in directions that aren’t in direct line-of-sight, effectively spreading around corners and around edges. The effect is more noticeable when the obstacle is similar in size to the wavelength, which is why radar signals can reach beyond buildings or around corners instead of being completely blocked. Other terms don’t describe this bending and spreading around edges, focusing instead on unrelated phenomena.