A three-phase transmission line has flat horizontal spacing with 2m between adjacent conductors. At a certain instant the charge on one of the outside conductors is 60, μC/km, and the charge on the center conductor and on the other outside conductor is - 30μC/km. The radius of each conductor is 0.8 cm. Neglect the effect of the ground and find the voltage drop between the two identically charged conductors at the instant specified.