• A circular coil with radius R sits flat on the table-top (in the x,y plane) with its center at the origin, and carries 5.0 A counter-clockwise to produce a 400 mT magnetic field intensity at the coil center. 
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• (a) draw the magnetic field direction at the coil center .
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• b) What magnetic field intensity does it produce along the z axis, at half a radius above the table.