Question

A wave of frequency $500\, Hz$ travels with a speed of $360 \,ms^{-1}$. The distance between two nearest points which are $60^{\circ}$ out of phase is

• A. 12 cm
• B. 18 cm
• C. 50 cm
• D. 24 cm

Answer 1

Answer: (A)

12 cm

Answer 2

Given, $v=360\, ms ^{-1}, \lambda=500\, Hz$
We know that, $v=f \lambda,\, \lambda=\frac{V}{f}$
Wavelength, $\lambda=\frac{360}{500}=0.72=72\, cm$
The distance between two nearest points which are $60^{\circ}$ out of phase
$=\frac{\lambda}{6}=\frac{72}{6}=12\, cm$