Theory of electricity

Molecule: The molecule is the smallest possible part of a physical element , Example : a molecule of water ( H2O ) is always water .

Atom: The atom is an element of the molecule ( it is no longer a physical element ) . Example : two atoms of hydrogen and one of oxygen give a molecule of water .

The atom is constituted by a nucleus around of which turn electrons . In elements like copper wires the electrons can leave atoms .

Electricity: If we connect something between the poles of a current’s generator we create an electric circuit  , electrons form a current that circulates from a pole to the other .

The electric current that circulates from the battery has three effects : it lights the bulb , it provokes the electrolysis of the water and it deviate the needle of the compass . The electric current has a thermal effect , a chemical effect and a magnetic effect ( a magnetic field can create the movement of an engine ) . We can compare an electric current to a liquid that circulates in pipes , An example is a central heating . The battery would correspond to the boiler and the bulb to a radiator .

We can generate an electric current by the chemistry ( battery, accumulator ) or by the magnetism ( dynamo, alternator ) .

The magnetic effect is reversible : a loud speaker produces a sound but it can also serve as microphone ( in an intercom ) .

The current can be direct , it circulates then in one way ( battery , accumulator ) , or it is alternative : it circulates once in a way

then in the other ( line, sounding signal ) .

The voltage of the line ( in France ) is 220 volts with a frequency ( curve of sinus ) of 50 Hertz ( 50 go and return by second ) .

We consider since the discovery of electricity that the current circulates between the pole + to the pole - . In reality this is the contrary because electrons are negative ( - ) .

Anecdote : If we drive in a potato a stem of copper and a stem of zinc we obtain a battery : the potato’s battery ( not very powerful ) .