Direction: In the Following Questions, A Statement of Assertion (A) I...
Both assertion (A) and reason (R) are true but reason (R) is not the correct explanation of assertion (A).
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Direction: In the Following Questions, A Statement of Assertion (A) I...
Assertion: Rainbow is an example of the dispersion of sunlight by the water droplets.
Reason: Light of shorter wavelength is scattered much more than light of larger wavelength.
The correct answer is option 'B' - Both assertion (A) and reason (R) are true but reason (R) is not the correct explanation of assertion (A).
Explanation:
Dispersion of sunlight by water droplets:
- When sunlight passes through water droplets in the atmosphere, it undergoes dispersion, which means it gets separated into its component colors.
- This dispersion occurs due to the phenomenon of refraction. The different colors of light bend at slightly different angles as they pass through the water droplets, resulting in the separation of colors.
Formation of a rainbow:
- When sunlight passes through water droplets in the atmosphere, it undergoes dispersion and forms a circular arc of colors in the sky, known as a rainbow.
- The primary rainbow consists of seven colors: red, orange, yellow, green, blue, indigo, and violet.
Explanation of the assertion:
- The assertion states that a rainbow is an example of the dispersion of sunlight by water droplets, which is correct.
- When sunlight enters a water droplet, it gets refracted, and the different colors of light are separated. This dispersion is responsible for the formation of a rainbow.
Explanation of the reason:
- The reason states that light of shorter wavelength is scattered much more than light of larger wavelength, which is also true.
- According to Rayleigh scattering, the scattering of light by particles or molecules is inversely proportional to the fourth power of the wavelength. This means that shorter wavelength light (blue and violet) is scattered much more than longer wavelength light (red and orange).
- This phenomenon is the reason why the sky appears blue during the day. The shorter wavelength blue light is scattered more by the molecules in the atmosphere, while the longer wavelength red light is scattered less.
Explanation of the correct answer:
- Both the assertion and reason are true. A rainbow is indeed an example of the dispersion of sunlight by water droplets, and light of shorter wavelength is scattered more than light of larger wavelength.
- However, the reason does not directly explain why a rainbow is formed. It provides a general statement about the scattering of light but does not specifically address the dispersion of sunlight by water droplets, which is the cause of a rainbow.
- Therefore, the reason is not the correct explanation of the assertion.
- Hence, the correct answer is option 'B'.
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