A horizontal ,straight wire carying 12.0A current from west to east is in the earth's magnetic field B.At this place,B is parallel to the surface of the earth ,points to the north and its magnitude is 0.04mT.Determine the magnetic force on 1m length of the wire.If mass of this length of wire is 50g.calculate the value of current in the wire so that its weight is balanced by the magnitude force.

1 answer

a) F = iLB
b) mg = iLb so i =mg/LB