Two long, parallel conductors carry currents in the same direction. Conductor A carries current of 150 A and is fixed firmly in position. Conductor B carries a current lB and is allowed to move freely up and down, parallel to conductor A. If the linear mass density of conductor B is 0.10 g/cm, what value of current lB will result in equilibrium when the distance between the two conductors is 2.5 cm? Hint: what forces are acting on conductor B?