A rectangular loop of wire with sides 0.240 and 0.554 m lies in a plane perpendicular to a constant magnetic field (see part a of the drawing). the magnetic field has a magnitude of 0.579 t and is directed parallel to the normal of the loop's surface. in a time of 0.117 s, one-half of the loop is then folded back onto the other half, as indicated in part b of the drawing. determine the magnitude of the average emf induced in the loop.