A transverse wave propagating on a stretched string of linear density $3 \times 10^{-4}\;kg-m^{-1}$ is represented by the equation $y=0.2 \sin (15 x +60 l)$ where x is in meters and l is in seconds . The tension in the string (in newton) is :

Question

\[\begin {array} {1 1} (a)\;0.24 & \quad (b)\;0.48 \\ (c)\;1.20 & \quad (d)\;1.80 \end {array}\]