why does northpole south pole repulsion takes placeand why not north-north pole repulsion and south-south pole

Question

physics

Answer 1

Actually, in magnetism, the repulsion is between poles of the same name. You can check that by using many magnets.

Take magnets A and B. On magnet A, mark one pole (e.g., with a drop of paint). Doesn't matter which one. Let us say that the North pole was picked.

Then find, on B, which pole is repulsed by the marked pole on A. Put a drop of paint on it.

Then pick up magnet C, find the pole that is repulsed by the marked pole of A. Another drop of paint.

Now: if the repulsion is between different names, then the marked pole on B is a south pole, same as the marked pole on C (they are both repulsed by A's north pole). Therefore, the marked poles on B and C should attract each other. They will not.

If the repulsion is between same names, then the marked poles on B and C are both N (same as A). They will repulse each other, the same way as they are both repulsed by A's marked pole.

In practice, the second case is observed. Therefore, same name poles repulse each other.

As to why, that is a different question.
Start at wikipedia.

http://en.wikipedia.org/wiki/Magnetism

The classical explanation is based on the "direction" of the lines of force of the magnetic field. Lines of field are often represented as coming out of a pole and going back into the other -- same as electricity is shown as going one way in a wire.

However, the lines of force are actually going both ways simultaneously (the same was as the electrical potential difference is going both ways at once in the wire -- electrons are pulled one way, positively charged ions travel the other way if they are free to do so).

The problem with the classical image is that: easy to show that lines coming out of two north poles will push against each other -- but waht about lines going into south poles, should they not pull both south poles together?

Einstein showed that, at some level, magnetic repulsion and electrical repulstion are the same thing. Electrostatic repulsions involved virtual photons as exchange particles for the force.

Answer 2

It doesn't. The repulsion is between like poles..N-N and S-S. The lines of magnetic force go from the north seeking pole to the south seeking pole of the magnet. When two like poles are in proximity, the lines of force oppose each other.

Answer 3

As Ironbrew said, it doesn't. Perhaps you are noticing that magnets will attempt to align in a magnetic field. For example a compass will point toward the north. There is repulsion from like poles.