Polarity of a horseshoe shaped solenoid

[Abigaile]

Homework Statement

polarity of a horseshoe shaped solenoid given symbol for power source large line small line.
Current flows through the right end of the horsehoe and out of the left end.

The wire is wrapped in a CW direction if looking at the left end of the magnet.
The wire is wrapped in a ACW direction if looking at the right end of the magnet.

Im confused that the current direction using right hand grip rule and wrap direction of the coil viewed from the ends are giving the opposite conflicting result.

Homework Equations

none

The Attempt at a Solution

Assuming conventional current from positive (large line) to negative (small line).

Viewing the right end current direction is ACW so this should be North
Viewing the left end current direction is CW so this should be South

Is this correct or should I consider the rules as if the horseshoe was broken in half like a wishbone?

Thanks..

 

[tiny-tim]

Welcome to PF!

Hi Abigaile! Welcome to PF!

polarity of a horseshoe shaped solenoid …
Current flows through the right end of the horsehoe and out of the left end.

The wire is wrapped in a CW direction if looking at the left end of the magnet.
The wire is wrapped in a ACW direction if looking at the right end of the magnet.

Im confused that the current direction using right hand grip rule and wrap direction of the coil viewed from the ends are giving the opposite conflicting result.

No.

Wrap your right hand around the left end of the solenoid, so that your fingers are curling the same way as the current …

your thumb then points into the solenoid.

Now slide your hand all the way round the solenoid to the other end …

your thumb now points out of the solenoid …

isn't that what you expect, one end north and the other end south? ​

 

[Abigaile]

Hi Abigaile! Welcome to PF!


No.

Wrap your right hand around the left end of the solenoid, so that your fingers are curling the same way as the current …

your thumb then points into the solenoid.

Now slide your hand all the way round the solenoid to the other end …

your thumb now points out of the solenoid …

isn't that what you expect, one end north and the other end south? ​

Hi Tim

does that mean left end is south and right end is north?

 

[tiny-tim]

Yes!

(or the other way round … i can't remember )

 

[asteriatic]

I would first clarify the terminology being used. In this context, the horseshoe shaped solenoid is most likely referring to a horseshoe magnet with a wire coil wrapped around it, rather than a solenoid which is typically a cylindrical coil of wire. With that being said, the polarity of a horseshoe magnet is determined by the direction of the magnetic field lines, which in turn is determined by the direction of current flow in the wire coil.

Based on the given information, it seems that the power source is connected to the right end of the horseshoe magnet, with current flowing through the coil in a clockwise direction when viewed from the left end. This would result in a north pole at the right end and a south pole at the left end, based on the right hand grip rule. However, when looking at the horseshoe magnet as a whole, the north pole is typically labeled as the end where the magnetic field lines exit and the south pole as the end where they enter. This would mean that the left end of the horseshoe magnet is actually the north pole and the right end is the south pole.

In terms of the conflicting results, it is important to remember that the right hand grip rule and the direction of coil wrapping are simply conventions used to determine the direction of current flow and the resulting magnetic field. It is possible that the conflicting results are due to a difference in the conventions being used. To avoid confusion, it may be helpful to label the poles of the horseshoe magnet based on the direction of the magnetic field lines, rather than the direction of current flow.