Neurons in our bodies carry weak currents that produce detectable magnetic fields. Atechnique called magnetoencephalography, or MEG, is used to study electrical activity inthe brain using this concept. This technique is capable of detecting magnetic fields as weakas 1.0 ? 10-15 T. Model the neuron as a long wire carrying a current and find the current itmust carry to produce a field of this magnitude at a distance of 4.8 cm from the neuron.