Electricity (Intro)


Charging by contact or friction and charging by induction

Electrodynamics: Electric current

Electric energy

Difference between static electricity and "normal" (or current) electricity

The gold leaf electroscope

Electricity Quiz



Magnetic force

Magnetism and electricity are two sides of the same coin: electromagnetism.

Similarly to electricity, there is a magnetic force and a magnetic energy associated to it.

In magnetism we talk of the south pole and the north pole. Like poles repel each other and opposite poles attract each other. That is to be similar to the positive and negative charges in electrostatics. In electrostatic you can isolate a charge, negative or positive.

However, this is not possible with magnetism. There is no such a thing as a magnetic monopole, i.e., you can never separate the north pole from the south pole. Every piece of magnetic material,no matter how small it is, will alway present a south pole and a north pole.

Magnetism was first observed in stones, which are naturally magnetic. Magnetite is a typical one.

Magnets are very important in technology. Electromagnets have become more common than natural ones.

In an electromagnet, the magnetic force is produce by an electric current. This way it is possible to produce very strong forces.

This principle is also used in motors and generators.