A : Light waves can be polarised.
R : All electromagnetic waves move with same speed in vacuum.

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.

### Step 1: Understand the Assertion (A)
The assertion states that "Light waves can be polarised."
- Light is an electromagnetic (EM) wave, and it can indeed be polarized. Polarization refers to the orientation of the oscillations of the wave. Light waves can be polarized because they are transverse waves, meaning the electric field oscillates perpendicular to the direction of wave propagation.

### Step 2: Understand the Reason (R)
The reason states that "All electromagnetic waves move with the same speed in vacuum."
- This statement is true. All electromagnetic waves, including light, radio waves, X-rays, etc., travel at the speed of light in a vacuum, which is approximately \(3 \times 10^8\) meters per second. This speed is a universal constant.

### Step 3: Analyze the Relationship Between A and R
Now we need to determine if the reason explains the assertion.
- While both statements are true, the reason does not explain why light waves can be polarized. The polarization of light is due to its transverse nature, not directly because all EM waves travel at the same speed.

### Conclusion
- The assertion (A) is correct: Light waves can be polarized.
- The reason (R) is also correct: All electromagnetic waves move with the same speed in vacuum.
- However, the reason does not explain the assertion.

Thus, the correct answer is that both statements are true, but the reason does not explain the assertion.

### Final Answer:
Both A and R are true, but R does not explain A.

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