A telephone cable at a place has four long straight horizontal wires carrying a current of $1.0 \;A$ in the same direction east to west. The earth magnetic field at the place is $ 0.39 \;G$ and the angle of dip is $35^{\circ}$. The magnetic declination is nearly zero. what are the resultant magnetic fields at points $ 4.0 \;cm$ below the cable ?