A magnetic sorting channel in a recycling system is shown viewed from above in the diagram below.
Two permanent magnets are placed on opposite sides of the channel. The magnet on the left has its North (N) pole facing inwards, and the magnet on the right has its South (S) pole facing inwards.
Which of the following correctly describes the magnetic field lines in the gap inside the sorting channel?
Straight parallel horizontal lines with arrowheads pointing from the North pole on the left to the South pole on the right.
Straight parallel horizontal lines with arrowheads pointing from the South pole on the right to the North pole on the left.
Curved field lines looping outwards and backwards onto their own respective magnets, with no lines crossing the gap between the left and right poles.
Repelling curved lines that bend away from the center of the channel, pointing vertically upwards and downwards as if the poles were repelling.