Magnetism

[Magnetism]

Topic Elements

Measurements and Standards
1-D Motion
Vectors
2-D Motion
Forces & Newton's Laws of Motion
Work & Energy
Momentum (& Conservation)
Rotational Motion
Thermodynamics
Vibrations & Waves
Sound
Electric Force & Fields
Capacitance &
Direct Current Circuits
Magnetism
Reflection & Refraction

Review Material

Questions

Formulas

Calculator

What creates magnetic fields?

Magnetic fields are caused by moving charges. (In other words, when there is current, there is a magnetic field.)

Quintessential Concepts

Magnetism, like electric fields produce both attractive and repulsive forces. When an object is magnetized, two poles are created. As in earth's magnetic poles, they are labeled (designated as) north and south. Now that works sort of like the electric charges positive and negative.

Like poles repel and unlike poles attract
Direction: arrows always point from North to South
it's a vector! (if you didn't notice that already)

Just thought you'd like to know that the Earth doesn't follow these conventions exactly. The Earth's North pole is actually the Magnetic South pole and vice versa. That's why a compass' north arrow points to the Earth's North pole.

[compass]

Domains

Magnetic domains are the basic building blocks of our conception of magnetism. Every object has many domains, a section of object that has a magnetic orientation (arrow pointing in some direction). In a magnetically neutral object, the domains have all sorts of random orientations (and they all seem to cancel each other out...it's that vector thing). The domains of magnetized objects, however, all point in one direction.

Magnetic Force