Question
Question: In traffic signals ………. Color light is used to stop vehicles because it is having …….Wavelength....
In traffic signals ………. Color light is used to stop vehicles because it is having …….Wavelength.
Solution
We know, when light incident on extremely small tiny fine particles or objects the object deflects the light in different directions which is a scattering use law of Rayleigh scattering to explain the statement given in question. Red light has lowest frequency while blue has greatest frequency than red therefore red scatters least.
Complete answer:
We know that when light from the sun travels through the atmosphere to reach the surface of earth. During this path through the atmosphere sunlight is scattered by the molecules of air, dust particles, water vapor, smoke and many more so we can say the atmosphere contains fine particles of dust smoke etc. the size of these particles is much larger than the size of molecules of air present in the atmosphere.
So when ray from sum incidents on the fine particles rays have different wavelengths scattered. However scattering is different for different colors since the size of particles is very fine as compared to wavelength. In the same passion we will see phenomena of scattering in traffic signals.
We know that traffic signals have three light red, yellow, and green. As we know red light is used to stop vehicles. The reason behind is red light is having longer wavelength. The color goes under less scattering for the color which is having longer wavelength. Red light is used to show danger signs or signals because red light is scattered the least by molecules. Result of scattering is inversely related to the fourth power of wavelength of visible light since red light has the highest value of wavelength among all the visible colors. We can see it scattered the least. Therefore the red light can travel the longest distance through any fine particle. Hence in traffic signals red color light is used to stop vehicles because it is having the highest wavelength.
Note:
Red has the highest wavelength like red blue has least wavelength therefore the most while red scatters least our eye is most sensible to red. Beyond the atmosphere the sky will look dark/black since beyond atmosphere no scattering has occurred since no fine particles are present.