A transverse wave is represented by : $\;y=\large\frac{10}{\pi} sin (\large\frac{2 \pi}{T} t - \large\frac{2 \pi}{\lambda} x)\;$ . For what value of the wavelength the wave velocity is twice the maximum particle velocity ?

Question

$(a)\;40\;cm\qquad(b)\;20\;cm\qquad(c)\;10\;cm\qquad(d)\;60\;cm$