ANS:B - scattering

Scattering is a phenomenon that occurs when waves encounter obstacles or irregularities in a medium, causing them to change direction and spread out in different directions. This phenomenon is commonly observed with various types of waves, including electromagnetic waves such as light, X-rays, and radio waves, as well as acoustic waves like sound waves. There are several types of scattering, including:

1. Rayleigh Scattering: This type of scattering occurs when waves interact with particles or obstacles much smaller than the wavelength of the incident wave. Rayleigh scattering is responsible for the blue color of the sky and the reddening of the sun during sunrise and sunset. It is more effective at scattering shorter wavelengths, such as blue and violet light, compared to longer wavelengths.
2. Mie Scattering: Mie scattering occurs when waves interact with particles or obstacles that are comparable in size to the wavelength of the incident wave. Unlike Rayleigh scattering, Mie scattering is less wavelength-dependent and can occur with all colors of light. It is often observed in phenomena such as the scattering of light by clouds, haze, and dust particles.
3. Raman Scattering: Raman scattering involves the inelastic scattering of photons by molecules. When light interacts with molecules, some of the scattered light undergoes a change in energy due to interactions with the molecular vibrations or rotations. Raman scattering is used in spectroscopy to analyze the vibrational and rotational modes of molecules.
4. Compton Scattering: Compton scattering is a type of scattering that occurs when X-rays or gamma rays interact with matter, typically free electrons. In this process, the incident photon transfers some of its energy to the electron, causing it to recoil, and the photon is scattered at a different angle with reduced energy.

Scattering plays a crucial role in various natural phenomena, such as the color of the sky, the visibility of stars, the formation of rainbows, and the behavior of waves in the ocean. It also has practical applications in fields such as remote sensing, astronomy, atmospheric science, and materials characterization.