A magnet is hung by a string and then placed near a wire as shown. When the switch is closed, the magnet rotates such that the ends of the magnet move as indicated by the arrows. At the instant the switch is closed determine:
a) the direction of the current through the wire segment nearest the magnet.
b) the direction of the net force exerted by the magnet on the wire segment at the instant that the magnet is in the position shown.
Right hand rule
The Attempt at a Solution
For a) I know that the B field must be pointing in the opposite direction of magnet because the south pole vector points toward the bar magnet for its self. And by the rotation it's being repelled. By pointing my thumb in the direction of current and curling my fingers around the wire so that they end up away from the bar magnet I find that the current must be flowing counterclockwise.
For b) the net force must be in the right direction because the field lines of the south pole, which is closest to the wire, point in the right direction.
Yay or nay? Thanks for any help.
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