A : The radiation pressure due to light waves is maximum when the surface is a perfect reflector.
R : The momentum transfer by the photons to a perfectly reflecting surface is maximum.

Options

A. If both Assertion & Reason are true and the reason is the correct explanation of the assertion, then mark (1)
B. If both Assertion & Reason are true but the reason is not the correct explanation of the assertion, then mark (2)
C. If assertion is true statement but Reason is false, then mark (3)
D. If both Assertion and Reason are false statements, then mark (4)

Answer

To solve the question, we need to analyze the assertion (A) and the reason (R) provided in the context of electromagnetic waves and radiation pressure.

### Step-by-Step Solution:

1. **Understanding Radiation Pressure**:
Radiation pressure is the pressure exerted by electromagnetic radiation on a surface. It is related to the momentum of the photons hitting the surface.

2. **Assertion (A)**:
The assertion states that "The radiation pressure due to light waves is maximum when the surface is a perfect reflector." This is true because a perfect reflector will reflect all incoming light without absorbing any energy, leading to the maximum change in momentum.

3. **Momentum Transfer**:
When light (photons) strikes a surface, they impart momentum to that surface. For a perfectly reflecting surface, the momentum change is maximized. If a photon with momentum \( p \) strikes the surface and is reflected back, the change in momentum is \( \Delta p = p_{\text{final}} - p_{\text{initial}} = p - (-p) = 2p \).

4. **Reason (R)**:
The reason states that "The momentum transfer by the photons to a perfectly reflecting surface is maximum." This is also true, as we just calculated that the change in momentum for a perfectly reflecting surface is indeed \( 2p \), which is the maximum possible change.

5. **Conclusion**:
Since both the assertion (A) and the reason (R) are true, and the reason correctly explains the assertion, we conclude that both statements are correct.

### Final Answer:
Both the assertion (A) and the reason (R) are correct, and the reason explains the assertion.

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