A 47x10-6, uniform magnetic field is directed to the left in the plane of the paper. A wire, W, lying perpendicular to the plane of the paper carries a current I. The resultant magnetic field at D (10cm from the wire is zero).
a) What must be the direction of the current I? explain
b) What is the magnitude of the current?
c) If A is the same distance from the wire as is D, draw the direction of the result magnetic field at point A.