Assertion : Sound waves cannot be polarised.
Reason : Sound waves are longitudinal in nature.

Options

A. If both assertion and reason are true and reason is the correct explanation of assertion.
B. If both assertion and reason are true but reason is not the correct explanation of assertion.
C. If assertion is true but reason is false.
D. If both assertion and reason are false.

Answer

To analyze the given question about sound waves and their ability to be polarized, we will break down the assertion and reason step by step.

### Step 1: Understanding the Assertion
The assertion states that "Sound waves cannot be polarized."

- **Explanation**: This statement is true. Polarization is a property of waves that allows them to oscillate in a particular direction. Sound waves, being mechanical waves, do not exhibit polarization.

### Step 2: Understanding the Reason
The reason provided is "Sound waves are longitudinal in nature."

- **Explanation**: This statement is also true. Sound waves are classified as longitudinal waves, meaning that the particles of the medium through which the sound travels vibrate parallel to the direction of wave propagation.

### Step 3: Connecting Assertion and Reason
Now, we need to connect the assertion with the reason.

- **Explanation**: The reason explains why sound waves cannot be polarized. In longitudinal waves, the particle motion is parallel to the direction of the wave, which means that there is no perpendicular component of the wave that can be isolated for polarization. In contrast, transverse waves (like light waves) can be polarized because their particle motion is perpendicular to the direction of wave propagation.

### Step 4: Conclusion
Both the assertion and reason are true, and the reason correctly explains the assertion.

- **Final Statement**: Therefore, the correct conclusion is that both the assertion and reason are true, and the reason is the correct explanation of the assertion.