Assertion: Radio waves can be polarised.
Reason: Sound waves in air are longitudinal in nature.

Options

A. Both A and R true and R is the correct explanation of A
B. Both A and R are true but R is not a correct explanation of A
C. A is true but R is false
D. A is false but R is true

Answer

To solve the question, we need to analyze both the assertion and the reason provided.

### Step 1: Analyze the Assertion
The assertion states that "Radio waves can be polarised."
- Radio waves are a type of electromagnetic radiation, which are transverse waves.
- Transverse waves can indeed be polarized because their oscillations occur perpendicular to the direction of wave propagation.
- Therefore, the assertion is **true**.

### Step 2: Analyze the Reason
The reason states that "Sound waves in air are longitudinal in nature."
- Sound waves are mechanical waves that require a medium to travel and are classified as longitudinal waves.
- In longitudinal waves, the oscillations occur in the same direction as the wave propagation.
- Thus, this statement is also **true**.

### Step 3: Determine the Relationship Between Assertion and Reason
- While both statements are true, they refer to different types of waves: the assertion discusses radio waves (electromagnetic, transverse), while the reason discusses sound waves (mechanical, longitudinal).
- The reason does not explain the assertion, as the properties of sound waves do not affect the polarization of radio waves.

### Conclusion
Since both the assertion and reason are true, but the reason does not correctly explain the assertion, the correct answer is:
**Both assertion and reason are true, but the reason is not a correct explanation for the assertion.**

### Final Answer
**Option B: Both assertion and reason are true, but the reason is not a correct explanation for the assertion.**

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