Question about north and south poles of a magnet.

In summary, the reason for the attraction between the north and south poles of magnets is due to the energy of the system, which is true for all types of systems including those involving gravity and chemistry. This preference for lower energy states explains why in general the north pole attracts the south pole, and in circuits with current flowing in the same direction, the south pole of one electromagnet will attract the north pole of another electromagnet. This also applies to permanent magnets, such as bar magnets, where the north and south poles attract each other due to the energy of the system.
  • #1
Pulzz
6
0
I've always been taught: North poles attract south poles. Yesterday after studying electromagnetism, I've a question to ask. Here's a diagram:
4tXhD.png

In circuits like these, this is how the north and south poles of these electromagnets are defined. Now my question is, is the reason that the South pole of the first electromagnet(Its backside) attracted to the front of the electromagnet in the back because the two circuits have current flowing in the same direction? Is this why in general the north pole attracts the south pole? How does this work in a permanent magnet such as a bar magnet?
 
Physics news on Phys.org
  • #2
Hi there
Welcome to PF :smile:

Pulzz said:
I've always been taught: North poles attract south poles. Yesterday after studying electromagnetism, I've a question to ask. Here's a diagram:...
In circuits like these, this is how the north and south poles of these electromagnets are defined. Now my question is, is the reason that the South pole of the first electromagnet(Its backside) attracted to the front of the electromagnet in the back because the two circuits have current flowing in the same direction? Is this why in general the north pole attracts the south pole? How does this work in a permanent magnet such as a bar magnet?

in a straight wire carrying current, there are no north and south magnetic poles as the magnetic field is circular ( a loop) around the wirecheers
Dave
 
  • #3
davenn said:
Hi there
Welcome to PF :smile:
in a straight wire carrying current, there are no north and south magnetic poles as the magnetic field is circular ( a loop) around the wirecheers
Dave

I'm sorry, but I don't see how this answer is relevant to my question at all. My question is about two closed loops which produce a magnetic field as such:
curloo.gif
 
  • #4
now if you wind the wire into a coil, then you can create magnetic N and S poles ...

magnetic-field-in-a-straight-coil-of-wire.gif
 
  • #5
Pulzz said:
I'm sorry, but I don't see how this answer is relevant to my question at all. My question is about two closed loops which produce a magnetic field as such:

because you first drawings were showing straight sections of wire, so my answer was completely relevantD
 
  • #6
Pulzz said:
Now my question is, is the reason that the South pole of the first electromagnet(Its backside) attracted to the front of the electromagnet in the back because the two circuits have current flowing in the same direction? Is this why in general the north pole attracts the south pole?

No. It's to do with the energy of the system. Systems tend to prefer lower energy states. This holds for all sorts of systems including those involving gravity and chemistry.

http://physics.stackexchange.com/questions/64146/the-preference-for-low-energy-states
 

1. What is the difference between the north and south poles of a magnet?

The north and south poles of a magnet refer to the two opposite ends of a magnet. The north pole is the end that points towards the Earth's geographic north pole, while the south pole points towards the Earth's geographic south pole. These poles have opposite magnetic properties and attract or repel each other.

2. How are the north and south poles of a magnet determined?

The north and south poles of a magnet are determined by using a compass. The end of the magnet that points towards the Earth's geographic north pole is considered the north pole of the magnet. This is because the Earth's geographic north pole is actually a magnetic south pole, so the north pole of a magnet will be attracted to it.

3. Can the north and south poles of a magnet be separated?

No, the north and south poles of a magnet cannot be separated. If a magnet is cut in half, each piece will still have a north and south pole. This is because the magnetic properties of a magnet are determined by its molecular structure, not by its physical shape.

4. What happens when the north and south poles of two magnets are brought together?

When the north and south poles of two magnets are brought together, they will either attract or repel each other depending on their orientation. Two north poles or two south poles will repel each other, while a north pole and a south pole will attract each other.

5. How do the north and south poles of a magnet affect its magnetic field?

The north and south poles of a magnet are responsible for creating a magnetic field around the magnet. The magnetic field lines produced by the north pole of a magnet will flow towards the south pole, creating a closed loop. The strength of the magnetic field is strongest at the poles and decreases as you move away from them.

Similar threads

B Is the Direction of Magnetic Fields Truly Conventional?
    • Electromagnetism
Replies
6
Views
627
A Magnetization and magnet poles
    • Electromagnetism
Replies
10
Views
736
B Changing magnetic polarity of an electromagnet
    • Electromagnetism
Replies
10
Views
527
Magnetism -- Clarification about North and South magnetic poles
    • Electromagnetism
Replies
15
Views
1K
Lenz's law and instantaneous change in inductor's current
    • Electromagnetism
Replies
3
Views
982
B Magnetic generator multiple poles. Cancel out or short circuit?
    • Electromagnetism
Replies
8
Views
994
Magnetic Attraction: Is Bar Magnet Symmetrical?
    • Electromagnetism
Replies
3
Views
1K
Magnet's attraction force on a piece of iron
    • Electromagnetism
Replies
1
Views
1K
Work performed by a magnetic field
    • Electromagnetism
Replies
4
Views
9K
Deduction about Magnetic Poles surrounding a Conductor
    • Introductory Physics Homework Help
2
Replies
40
Views
898

Hot Threads

Recent Insights

Back
Top