According to Rayleigh scattering, the intensity of scattered light is:

AIIMS CRE, SNO-2024

General Knowledge

Easy

Appeared in: AIIMS CRE, SNO-2024

Explanation

Rayleigh's law of scattering states that the intensity of scattered light is inversely proportional to the fourth power of its wavelength (I ∝ 1/λ⁴).
This physical law explains that shorter wavelengths of light (such as blue and violet) are scattered much more strongly and in all directions compared to longer wavelengths (such as red and orange).
The condition for Rayleigh scattering is that the scattering particles (e.g., air molecules) must be significantly smaller in diameter than the wavelength of the light being scattered.

Option A: This is the opposite of Rayleigh's law. It would incorrectly imply that longer wavelengths (like red light) scatter more than shorter wavelengths (like blue light).
Option C: The intensity of Rayleigh scattering is fundamentally dependent on the wavelength. The inverse fourth-power relationship shows this dependence is very strong.
Option D: The law specifies an inverse relationship to the fourth power (1/λ⁴), not a direct relationship to the square (λ²). The power of 4 indicates a much more dramatic change in scattering intensity with wavelength than a power of 2 would.

Visual 1: Diagram - A diagram illustrating Rayleigh scattering. It should show a beam of white light entering the atmosphere, with blue light waves being scattered in multiple directions by air molecules, while red light waves pass through more directly.
Visual 2: Infographic - An infographic comparing the scattering intensity of different colors in the visible spectrum. A bar chart could visually represent the 1/λ⁴ relationship, showing a very high bar for violet/blue and a very low bar for red.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Relationship between light wavelength and scattering intensity according to Rayleigh scattering as background academic context rather than a clinical decision trigger.
While a physics concept, understanding light scattering is foundational to technologies used in medicine, such as pulse oximetry. A pulse oximeter measures blood oxygen saturation by analyzing the differential absorption and scattering of red and infrared light passing through a patient's finger.
Principles of light scattering are also used in laboratory techniques like nephelometry and turbidimetry to measure the concentration of suspended particles in a fluid sample, such as antigen-antibody complexes in immunoassays.
What if? - If light scattering were proportional to wavelength instead of inversely, our sky would appear reddish during the day, and sunsets would look blue, as the longer red wavelengths would be scattered most.

How to Approach the Question

First, identify the core concept of the question, which is 'Rayleigh scattering'.
The question asks for the relationship between the 'intensity of scattered light' and 'wavelength'. This is a factual recall question based on a physical law.
Recall the fundamental formula for Rayleigh scattering: Intensity (I) is proportional to 1 divided by the fourth power of the wavelength (λ), or I ∝ 1/λ⁴.
Translate this formula into words: 'inversely proportional to the fourth power of wavelength'.
Compare this statement with the given options to find the exact match.

Concept Tested & Keywords

Concept Tested: Relationship between light wavelength and scattering intensity according to Rayleigh scattering.
Stem keywords: Rayleigh scattering, intensity, scattered light, wavelength
Lead-in keywords: BEST, MOST RELEVANT CLUE

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