일반물리학 2 — Magnetic Fields Due to Currents: Problem 27

27 A long solenoid with 10.0 turns/cm and a radius of 7.00 cm carries a current of 35.0 mA. A current of 5.00 A exists in a straight conductor located along the central axis of the solenoid. (a) At what radial distance from the axis will the direction of the resulting magnetic field be at 45.0° to the axial direction? (b) What is the magnitude of the magnetic field there?