Speed of sound is maximum in

Options

A. air
B. water
C. vaccum
D. solid

Answer

To determine in which medium the speed of sound is maximum among the given options (air, water, vacuum, and solid), we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Formula for Speed of Sound**:
The speed of sound (v) in a medium is given by the formula:
\[ v = \sqrt{\frac{E}{\rho}} \]
where \(E\) is the coefficient of elasticity of the medium and \(\rho\) is the density of the medium.

2. **Analyze the Given Options**:
- **Air**: Low density and low elasticity.
- **Water**: Higher density than air, but lower elasticity compared to solids.
- **Vacuum**: Sound cannot travel in a vacuum since there are no particles to transmit sound.
- **Solid**: Generally has high density and very high elasticity.

3. **Compare the Coefficient of Elasticity and Density**:
- In solids, the coefficient of elasticity (E) is much larger than in liquids and gases due to the tightly packed structure of particles.
- Although solids also have high density (\(\rho\)), the increase in elasticity significantly outweighs the effect of density on the speed of sound.

4. **Conclusion**:
Since the coefficient of elasticity in solids is much greater than that in liquids and gases, the speed of sound is maximum in solids. Therefore, the correct answer is:
\[ \text{Speed of sound is maximum in solids.} \]

### Final Answer:
The speed of sound is maximum in solids.