Question

A sine wave of wavelength ${}^{\prime }{\lambda }^{\prime }$ is travelling in a medium. What is the minimum distance between two particles of the medium which always have the same speed?

• A. $\lambda$
• B. $\frac{\lambda }{2}$
• C. $\frac{\lambda }{3}$
• D. $\frac{\lambda }{4}$

Answer 1

Answer: (A)

$\lambda$

The two particles of the medium containing sine wave will have samspeed only when both of the particles will be in identical position, have same phase. For same phase the particles should be in $n\lambda$ separation where $n=1,2,\mathrm{3...}$. Therefore, minimum separation is $\lambda$.