A student forms a short electromagnet by winding 100 turns of wire around a wooden cylinder of diameter d = 2.0 cm. The coil is joined to a battery generating a current of 2.0 A in the wire.
(i) Find out the magnetic moment of the device?
(ii) Determine at what axial distance z d will the magnetic field of this dipole encompass the magnitude 5.0 µT (around one-tenth that of Earth's magnetic field)?