Which statement correctly describes magnetic field lines?
O
A. They form loops by joining north pole to south pole.
O
B. They show the direction a south pole will point.
O
C. They form loops by joining positive charge to negative charge.
O
D. They are parallel with one another.

Two charged particles, q1 and q2, are located on the x-axis, with q1 at the origin and q2 initially at x1 = 12.2 mm. in this configuration, q1 exerts a repulsive force of 2.62 µn on q2. particle q2 is then moved to x2 = 18.0 mm. what is the force (magnitude and direction) that q2 exerts on q1 at this new location? (give the magnitude in µn.)