34-A An electromagnetic wave front. The 34-B Gaussian surface for a plane electro- plane representing the wave front moves to magnetic wave. the right (in the positive x-direction) with speed c. The electric field is the same on the top and bottom sides of the Gaussian surface, so the total electric flux through the surface is Zero, Planar wave front E R B=D R R The electric and magnetic fields are uniform The magnetic field is the same on the left and behind the advancing wave front and zero in right sides of the Gaussian surface, so the total front of it. magnetic flox through the surface is zero