$$A $3-($GHz$),$y$-$polarized uniform plane wave propagates in the $+$x$-$direction in a nonmagnetic medium having a dielectric constant $2\mathrm{.}5$and a loss tangent $0\mathrm{.}05.$a$)$Determine the distance over which the amplitude of the propagating wave will be cut in half. b$)$Determine the intrinsic impedance, the wavelength, the phase velocity, and the group velocity of the wave in the medium. c$)$Assuming E$=$ay$50$sin$(6$$109$t$+$$3)($Vm$)$at x$=0,$write the instanta$-$neous expression for H $$for all t $$and x$.$