A solenoid of radius r = 1.25 cm and length {9 = 32.0 cm has 290 turns and carries 12.0 A. '3 (a) Calculate the ux through the surface of a disk-shaped area of radius R = 5.00 cm that is positioned perpendicular to and centered on the axis of the solenoid as in the figure (a) above. E w [b] Figure (b) above shows an enlarged and View of the same solenoid. Calculate the flux through the tan area, which is an annulus with an inner radius of a = 0.400 cm and outer radius of b = 0.800 cm. E w