Work Step by Step
Apply Lenz’s law to determine the direction of the induced current. The current pulse in the coil is in the counterclockwise direction as viewed from above. This creates an upward B field inside the brain. As the upward magnetic field in the brain increases, the induced current must make a downward field and flow clockwise (direction 1) to oppose the increasing flux. As the upward magnetic field in the brain decreases, the induced current must make an upward field and flow counterclockwise (direction 2) to assist the decreasing flux.