North and south pole in an electromagnet

In summary, an electromagnet has a constant N or S pole. The north pole is the end that attracts the south pole.
  • #1
brandontran87
4
0
Not sure if this should be in engineering or physics section. Sorry if I got it wrong.

How do I determine the north and south pole in an electromagnet? Do electromagnets have a constant N or S pole?

I am making a locking device where a neo magnet will hold a lid down tightly by sticking itself to a piece of steel placed inside the enclosure. I want to make that piece of steel an electromagnet so that when it turns on it will repel the neo magnet enough so I can open the lid. But to do that I need to be able to determine the poles on the electromagnet and keep it constant every time I run a current through the coil.

If I wrap the coil around the middle of the piece of steel will the opposite ends of the steel be the N or S poles?

Thanks in advance guys. If you guys have any suggestions for my project I would love to hear it. =)
 
Physics news on Phys.org
  • #2
right hand grab rule:

If you grab the electromagnet in your hand with the current in the coils flowing in the direction of your fingers, then if you stick your thumb out, it points in the direction of the magnet's north pole. Current is assumed to travel from the positive end of the battery to the negative.
 
  • #3
current flows from the negative to the positive in a battery. the electrons are pushed away from the negative and attracted to the positive.
 
  • #4
oops :blush:
 
  • #5
cragar said:
current flows from the negative to the positive in a battery. the electrons are pushed away from the negative and attracted to the positive.

But the hand rules, left hand rule etc use the conventional( +to -) current direction.
 
Last edited:
  • #6
I think it's positive to negative...http://en.wikipedia.org/wiki/Electric_current#Current_flow I think positive means there is an abundance of electrons so they move to a negative? Not sure...

Anyways, do you guys think my idea will work? If I turn the electromagnet on, will the poles stay at the same spot every time?
 
  • #7
with direct current, yes the poles should stay in the same place.
 
  • #8
I agree with dadface and that is why I wrote "Current is assumed to travel from the positive end of the battery to the negative." (for hand rules) :)
 
  • #9
k I am sure you guys are right about the hand rules and everything , but how can electrons flow from positive to negative , maybe i am missing something.
 
  • #10
cragar said:
k I am sure you guys are right about the hand rules and everything , but how can electrons flow from positive to negative , maybe i am missing something.

You are not missing something the true direction is from -to +.The hand rules use the incorrect conventional direction which goes the other way.I think these rules were devised long before the true current direction was known and for some reason they have remained in the texts.
 
  • #11
ok thanks for clarifying
 
  • #12
Hi
some one please help/ i am ready to throw a screaming fit...

I HAVE HOME MADE ELECTRO MAGS...THEY ARE GOOD ONES...POWERED BY A 12 VOLT CAR BATTERY (DC),...WHY IS IT THAT ONE END OF THE ELECTRO MAGNETS...EITHER NORTH OR SOUTH WILL ATTRACT BOTH ENDS (NORTH OR SOUTH ) OF MY NEODYMIUM MAGNETS ...TRIED EVERYTHING...EVEN SOBBING INTO MY PILLOW . WHAT I NEED IS FOR ONE END OF THE ELECTRO, EITHER NORTH OR SOUTH TO REPEL ONE END OF THE NEO AND ATTRACT THE OTHER END OF THE NEO...BEGGING FOR HELP...JIM
 
Last edited:

1. What is the difference between the north and south poles in an electromagnet?

The north and south poles in an electromagnet refer to the two ends of the magnet where the magnetic field is strongest. The north pole is where the magnetic field lines point towards, while the south pole is where the magnetic field lines point away from.

2. How does an electromagnet's strength change with the north and south poles?

The strength of an electromagnet is determined by the number of turns in the wire, the amount of current flowing through the wire, and the material of the core. The north and south poles do not affect the strength of an electromagnet, but rather indicate the direction of the magnetic field.

3. Can the north and south poles of an electromagnet be reversed?

Yes, the polarity of an electromagnet can be reversed by changing the direction of the current flow. This can be achieved by reversing the connection of the battery or power source to the electromagnet.

4. How are the north and south poles of an electromagnet used in everyday life?

Electromagnets with oppositely charged poles are used in various devices such as motors, generators, speakers, and MRI machines. They are also used in everyday objects like doorbells, refrigerators, and credit cards.

5. What is the purpose of the north and south poles in an electromagnet?

The north and south poles in an electromagnet allow for the creation of a magnetic field, which can be used to attract or repel other magnets. This property makes electromagnets useful in a wide range of applications, from transportation to medical technology.

Similar threads

  • Electromagnetism
Replies
10
Views
612
  • Electromagnetism
Replies
10
Views
374
  • Electromagnetism
Replies
6
Views
527
Replies
15
Views
1K
Replies
3
Views
942
  • Electromagnetism
Replies
6
Views
623
Replies
5
Views
2K
Replies
8
Views
932
  • Electromagnetism
Replies
4
Views
9K
  • Classical Physics
Replies
7
Views
790
Back
Top