1) the strength of an electromagnet can be increased bya. replacing the iron core with a steel coreb. using coils of fewer turns on the electromagnetc. passing a larger current through the electromagnetd. using thinner wire for the coils2) the magnetic field lines in the middle of a current-carrying solenoid area. spiralsb. circlesc. parallel to the axis of the solenoidd. perpendicular to the axis of the solenoid3) two parallel conductors have current flowing through them. in the first instant, the current is flowing in the opposite direction to each other. what are the forces acting on the wires in each case? a. attraction and repulsion respectivelyb. repulsion and attraction respectivelyc. attraction for both casesd. repulsion for both cases