An overhead electric power line carries a maximum current of 165 A. What is the magnitude of the magnetic field at a point 2.40 m directly below the power line? Soo... I = 165A L = 2.40m Equations i have learnt areee (1) F = ILBsin(theta) (2) F = |q|vBsin(theta) (3) r = mv / |q|B (4) B = (constant)I/R im unsure . i tried equation 4 . but that didnt work. any help would be awesome!