An air-filled toroidal solenoid has 390 turns of wire, a mean radius of 15.0 cm , and a cross-sectional area of 5.00 cm2 .
Part A. If the current is 5.40 A , calculate the magnetic field in the solenoid.
Part B. Calculate the self-inductance of the solenoid.
Part C. Calculate the energy stored in the magnetic field.
Part D. Calculate the energy density in the magnetic field.
Part E. Find the answer for part D by dividing your answer to part C by the volume of the solenoid.