Question

Assertion Speed of sound is more in liquids and solids than gases.
Reason Liquids and solids have higher densities than gases.

• A. Both Assertion and Reason are correct and Reason is the correct explanation of Assertion.
• B. Both Assertion and Reason are correct but Reason is not the correct explanation of Assertion.
• C. Assertion is correct but Reason is incorrect.
• D. Assertion is incorrect but Reason is correct.

Answer 1

Answer: (B)

Speed of sound in a medium is given as $v=\sqrt{\frac{B}{\rho }}\dots$ (i) where, $B$ is the bulk modulus and $\rho$ is the density of the medium. Since, solids and liquids are much more difficult to compress than gases, so they have much higher values of bulk modulus. Also, generally solids and liquids have higher mass densities ( $\rho )$ than gases. But corresponding increase in both the modulus $B$ of solids and liquids is much higher. So, in accordance to Eq. (i), we can say that sound waves travel faster in solids and liquids. Therefore, Assertion and Reason are correct but Reason is not the correct explanation of Assertion.