Last modified on 10 November 2007, at 01:25

Electrodynamics/Magnetic Fields

Electric CurrentsEdit

In an electric field, especially in a conductor, charged particles will move according to the electromotive force applied by the electric field. In a practical sense, the charged particles in question are the free electrons in the conductor. Electrons are attracted to the areas of positive charge, and are repelled from the area of negative charge.

The mass-flow of electrons through a conductor is known as electric current.

Units of CurrentEdit

The flow of electrons through a conductor is measured in Amperes. The electric potential that causes electrons to flow is measured in Volts.

MagnetsEdit

Since ancient times, people have known about special rocks and materials that display a certain attractive and repulsive force on other such rocks. Termed "magnets", the force between them operates on a similar principle to the electric force that we have studied so far.

All magnets have two sides or poles, dubbed "North" and "South". Like positive and negative charges, like poles repel and opposite poles attract. The magnetic force works over distance, with the effect of the magnet decreasing over distance.

InductionEdit

Electric currents, or moving electric fields produce a magnetic force.

Magnetic FieldsEdit

Like an electric field, there is a magnetic field that extends everywhere. the strength of the magnetic field is dependent on the location of magnets in the field. It is a vector field, so every point has both a strength and a direction.

We will discuss the mathematical determination of the magnetic field starting in the next chapter when we discussion the Biot-Savart Law.

Field of a CurrentEdit

Electromagnetism.svg

Magnetic field of a current carrying wire.png

Right-Hand RuleEdit

Right hand rule simple.png

Field of a MagnetEdit

Current model of a MagnetEdit

Basic Inductor with B-field.svg

SolenoidsEdit

Solenoids