If a is the size of scatterer and `lamda` is the wavelength of light then Rayleigh law of scattering is valid for

Options

A. `a=lamda`
B. `agtgtlamda`
C. `a=lamda//2`
D. `altltlamda`

Answer

To determine when Rayleigh's law of scattering is valid, we need to analyze the relationship between the size of the scatterer (a) and the wavelength of light (λ). Here’s a step-by-step solution:

### Step 1: Understand Rayleigh's Law of Scattering
Rayleigh's law states that the amount of scattering of light is inversely proportional to the fourth power of the wavelength. Mathematically, this can be expressed as:
\[ \text{Scattering} \propto \frac{1}{\lambda^4} \]

### Step 2: Identify the Condition for Validity
For Rayleigh's law to be applicable, the size of the scatterer (a) must be significantly smaller than the wavelength of light (λ). This condition can be expressed as:
\[ a \ll \lambda \]
This means that the size of the scatterer should be much less than the wavelength of the light being scattered.

### Step 3: Conclusion
Thus, Rayleigh's law of scattering is valid when the size of the scatterer (a) is much smaller than the wavelength of light (λ).

### Final Answer
Rayleigh's law of scattering is valid for \( a \ll \lambda \).

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