Question

If equation of a sound wave is $y=0.0015 \sin (62.8 x+314 t)$ then its wavelength will be

• A. 2 unit
• B. $0.3$ unit
• C. $0.1$ unit
• D. $0.2$ unit

Answer 1

Answer: (C)

The standard equation of sound wave is
$y=a \sin 2 \pi\left(\frac{x}{\lambda}+\frac{t}{T}\right)$
where a is amplitude, $\lambda$ is wavelength and $T$ is time period.
Given equation of wave is
$y=0.0015 \sin (62.8 x+314 t)$....(1)
Comparing given Eq. (1) with standard wave, we get
$\frac{2 \pi}{\lambda} =62.8$
$\Rightarrow \lambda =\frac{2 \pi}{62.8}=\frac{2 \times 3.14}{62.8}=0.1 \text { unit }$