Question

State whether the given statement is True or False :

Consider a sinusoidal travelling wave shown in figure. The wave velocity is $+40cm/s$. The phase difference between points $2.5cm$ apart will be $\frac{5\pi }{4}$ rad.

• A. True
• B. False

Answer 1

The correct option is A True

Clearly from figure, the wavelength is equal to the distance between two in-phase points.
Let us consider the points where it cuts the x-axis.

The in-phase points cut x-axis at 2.5cm and 6.5cm.

Thus the wavelength is $4cm$

These points have a phase difference of $2\pi$.

Thus phase difference between points $2.5cm$ apart=$\frac{2.5}{4}\times 2\pi$ $rad=\frac{5\pi }{4}rad$