A neophyte magnet designer tells you that he can produce a magnetic field B in vacuum that points everywhere in the x-direction and that increases in magnitude with increasing x. That is, B = B0(x/a)i, where B 0 and a are constants with units of teslas and meters, respectively. Use Gauss’s law for magnetic fields to show that this claim is impossible. (Hint: Use a Gaussian surface in the shape of a rectangular box, with edges parallel to the x-, y-, and z-axes.)