Maximum emf for a thin loop *** A long straight stationary wire is parallel to the y axis and passes through the point z=h on the z axis. A current I flows in this wire, returning by a remote conductor whose field we may neglect. Lying in the xy plane is a thin rectangular loop with two of its sides, of length ℓ, parallel to the long wire. The length b of the other two sides is very small. The loop slides with constant speed v in the x^ direction. Find the magnitude of the electromotive force induced in the loop at the moment the center of the loop has position x. For what values of x does this emf have a local maximum or minimum? (Work in the approximation where b≪x, so that you can approximate the relevant difference in B fields by a derivative.)