The Tyndall effect is due to scattering of light by the colloidal particles. The colloidal particles first absorb light and then a part of the absorbed light is scattered from the surface of the colloidal particles. Maximum scattered intensity being in a plane at right angles to the plane of incident light, the path becomes visible when seen from that direction.

Tyndall effect is the phenomenon of scattering of light by particles in a medium. It is named after the 19th-century Irish physicist John Tyndall, who first explained this effect.

Explanation of Tyndall Effect:
The Tyndall effect occurs when light passes through a medium containing small particles or droplets that are larger than the wavelength of light. These particles scatter the light in different directions, making it visible to the naked eye. The scattered light appears as a beam of light or a cone of light when observed from the side.

Scattering of Light:
When a beam of light encounters a particle in its path, it interacts with the particle. The interaction can be described as the absorption and re-emission of the light by the particle. This causes the light to change its direction and spread out in different directions.

Size of Particles:
The size of the particles or droplets in the medium plays a crucial role in the Tyndall effect. If the particles are smaller than the wavelength of light, they do not scatter the light significantly, and the effect is not observed. However, if the particles are larger than the wavelength of light, they scatter the light in all directions, making it visible.

Key Factors:
- The Tyndall effect is observed when the particles in the medium are larger than the wavelength of light.
- The intensity of the scattered light depends on the concentration of particles in the medium. Higher concentrations result in a more pronounced effect.
- The color of the scattered light depends on the wavelength of light. Shorter wavelengths (blue and violet) are scattered more than longer wavelengths (red and orange).

Applications of Tyndall Effect:
The Tyndall effect has various applications in different fields:
- It explains why the sky appears blue during the day. The particles in the Earth's atmosphere scatter the shorter blue wavelengths more than the longer red wavelengths, making the sky appear blue.
- It is used in industries to measure particle size and concentration in solutions.
- It helps in determining the purity of colloidal solutions by observing the intensity of the scattered light.

In conclusion, the Tyndall effect is due to the scattering of light by particles in a medium. It is a phenomenon observed when the particles are larger than the wavelength of light. The scattered light appears visible to the naked eye, and its intensity and color depend on the concentration and wavelength of light, respectively.