A solonoid 4.0 cm in raduis and 4 m in length has 5000 uniformly spaced turns and carries a current of 5.0A. Concider a plane circular surface (radius of 2cm) located at the center of the solonoid with its axis coinsidal with the axis of the solonoid. What is the magnetic flux through the surface. (1wb=1t-m^2)