Which of the following statements are true for wave motion ?

Options

A. Mechanical tansverse waves can propagate through all mediums.
B. Longitudinal waves can propagate through solids only.
C. Mechanical transverse waves can propagate through solid only.
D. Longitudinal waves can propagate through vacuum.

Explanation

To determine which statements are true for wave motion, let's analyze each statement one by one.

### Step-by-Step Solution:

1. **Statement 1: Mechanical transverse waves can't propagate through all mediums.**
- **Analysis**: This statement is false. Mechanical transverse waves can only propagate through solids, as they require an elastic medium. They cannot propagate through fluids (liquids and gases) because these mediums do not support shear stress, which is necessary for transverse wave motion.
- **Conclusion**: This statement is **false**.

2. **Statement 2: Longitudinal waves can't propagate through solids only.**
- **Analysis**: This statement is also false. Longitudinal waves, such as sound waves, can propagate through solids, liquids, and gases. They do not have a restriction to only solids.
- **Conclusion**: This statement is **false**.

3. **Statement 3: Mechanical transverse waves can't propagate through solids only.**
- **Analysis**: This statement is true. Mechanical transverse waves can propagate through solids but not through fluids (liquids and gases). Thus, they require a solid medium for propagation.
- **Conclusion**: This statement is **true**.

4. **Statement 4: Longitudinal waves can't propagate through vacuum.**
- **Analysis**: This statement is true. Longitudinal waves require a medium (solid, liquid, or gas) for propagation. Since a vacuum lacks any medium, longitudinal waves cannot propagate through it.
- **Conclusion**: This statement is **true**.

### Final Summary:
- **True Statements**:
- Statement 3: Mechanical transverse waves can't propagate through solids only.
- Statement 4: Longitudinal waves can't propagate through vacuum.

- **False Statements**:
- Statement 1: Mechanical transverse waves can't propagate through all mediums.
- Statement 2: Longitudinal waves can't propagate through solids only.