A loop of wire has the shape shown in the drawing. The top part of the wire is bent into a semicircle of radius r = 0.25m. The normal to the plane of the loop is parallel to a constantmagnetic field of magnitude 0.94 T. What is the magnitude of the change in the magnetic flux that passes throughthe loop when, starting with the position shown in the drawing, the semicircle is rotated through half a revolution?