A student makes a short electromagnet by winding 540 turns ofwire around a wooden cylinder of diameter d = 3.2 cm. Thecoil is connected to a battery producing a current of 4.3 A in thewire. (a) What is the magnitude of the magneticdipole moment of this device? (b) At what axialdistance z >> d will the magnetic fieldhave the magnitude 5.0 µT (approximately one-tenth that of Earth'smagnetic field)?
