$10$ Q$-2$ a$)$ A uniform plane wave propagates in the $-$ direction. The magnetic field points in The $+$y direction. In what direction does the electric field point? $15$ Q$-2$ b$)$ The electric field of a uniform plane wave has a magnitude of $3$V $/$ m$.$ The wave travels through plastic having permittivity equal to $\backslash$epsi $=2\backslash$epsi $\_0.$ What is the magnitude of the magnetic field intensity $($B$)$ in the plastic? $(\backslash$epsi $\_$o$=1/36\backslash$pi $910^9($c$^2/$N $$ m$^2).$ Take $\backslash$pi $=3$