Question

A sound wave has a wavelength $\lambda$. The distance between the first compression and the third rarefaction is

• A. $\lambda$
• B. $3\lambda$
• C. $3\lambda /4$
• D. $5\lambda /2$

Answer 1

Answer: (C)

$3\lambda /4$

$\because$ Distance between two consecutive Compression is $\lambda$ and the distance between one compression to next rarefection is equal to $\lambda /2$.

Hence, distance between first compression and the third rarefaction is $\lambda +\lambda +\lambda /2=5\lambda /2$