Question

When the midpoints of four consecutive troughs in a sound wave are joined, it constitutes a distance of $12cm$. What is the wavelength of the sound wave?

• A. $1cm$
• B. $4cm$
• C. $3cm$
• D. $6cm$

Answer 1

The correct option is B $4cm$

Wavelength ($\lambda$) is the distance between two consecutive crests or troughs in a sound wave.
Given that the distance between mid points of four consecutive troughs constitute a distance of $12cm$.


From the figure, $3\times \lambda =12cm$
$⟹$ Wavelength, $\lambda =\frac{12}{3}=4cm$