Download Quiz #5: Magnetic Fields The small currents in the neurons in the

Quiz #5: Magnetic Fields
The small currents in the neurons in the brain produce a net magnetic field. The
total field is quite complicated, but when all of the cancelling currents and fields
are added up, there is a net field that can be approximated as that of a loop of
current around the outside of the head. The field in the center of the loop (and thus
in the center of the head) has a magnitude of approximately 3.0 pT.
Let’s model this field as being due to the current in a single loop of wire, with loop
diameter 16 cm, the width of a typical head. Sketch a top view of the loop showing
a clockwise current, note the direction of the field in the center, and calculate what
current is necessary to produce a field of the noted magnitude at the center.