Question 134: Waves

Question

Given below are two statements : one is labelled as Assertion A and the other is labelled as Reason $\mathbf{R}$
Assertion A: A sound wave has higher speed in solids than gases.
Reason R: Gases have higher value of Bulk modulus than solids.
In the light of the above statements, choose the correct answer from the options given below

Accepted Answer

We know, speed of sound in a medium $$v = \sqrt {{B \over \rho }} $$ where B = bulk modulus, $\rho$ = 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.
i.e., $${B_{solid}} > {B_{liquid}} > {B_{gas}}$$
Generally solids and liquids have higher mass densities ($\rho$) than gases. But corresponding increase in bulk modulus is much higher.
So, $${v_{solid}} > {v_{liquid}} > {v_{gas}}$$
Hence, option C is correct.

Answer

Both $\mathbf{A}$ and $\mathbf{R}$ are true and $\mathbf{R}$ is the correct explanation of $\mathbf{A}$

Answer

$\mathbf{A}$ is false but $\mathbf{R}$ is true

Answer

$\mathbf{A}$ is true but $\mathbf{R}$ is false

Answer

Both $\mathbf{A}$ and $\mathbf{R}$ are true but $\mathbf{R}$ is NOT the correct explanation of $\mathbf{A}$

Waves

Choose the correct answer: