Magnet Movement When Charged Rod or Bar Magnet is Brought Near

[zapped]

Homework Statement

a bar of magnet is hung from a string through its center. A charged
rod is slowly brought up into the positions shown(down)
in what direstion will the magnet tend to rotate?
Suppose the charged rod were replaced by a bar magnet with the north pole on top.

N magnet S

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<<<< rod

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Homework Equations

in what direstion will the magnet tend to rotate? Is there a difference between what happens to the hanging magnet in the 2 situations? Explain why you either do or do not think so

The Attempt at a Solution

The positive charge of the rod will repell the magnet and it will rotate clockwise
if the rod were to be replace it will be the same
is it right?

 

[LowlyPion]

Maybe make an attempt to understand this?
http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/magfor.html#c2

 

[nlightner]

Your explanation is partially correct. When a charged rod is brought near a hanging bar magnet, the magnet will tend to rotate in the direction opposite to the movement of the rod. This is because the positive charge on the rod will create a magnetic field that is opposite to the magnetic field of the bar magnet. This creates a repulsive force between the two and causes the magnet to rotate.

If the charged rod were replaced by a bar magnet with the north pole on top, the direction of rotation of the hanging magnet would depend on the orientation of the bar magnet. If the north poles of the two magnets are facing each other, the hanging magnet will rotate in the opposite direction as before, since like poles repel. However, if the south pole of the bar magnet is facing the hanging magnet, the two magnets will attract each other and the hanging magnet will rotate in the same direction as the movement of the bar magnet. So, there can be a difference in the direction of rotation depending on the orientation of the bar magnet.

In both situations, there is a repulsive force between the two magnets, but the direction of rotation can be different due to the orientation of the bar magnet. Overall, the behavior of the hanging magnet will be similar in both cases, as it will still tend to rotate in response to the magnetic field created by the charged rod or bar magnet.