In the 21st century, it would seem that all the laws of nature were discovered . Magnetism, electricity, the molecular and atomic world are an open book. Moreover, many laws that were discovered more than a hundred years ago do not lose their relevance to this day, being the basis of the work of many familiar objects. First of all, we are talking about electricity. The name of Andre Ampère, the French physicist-inventor, not only gave the name to physical law, but is also widely known to physicists and schoolchildren around the world thanks to the phenomenon he described.
In 1820, based on the interaction of a magnetic needle and an electric current flowing through a wire described by Oersted, Ampere made a major discovery, called the Ampere Law. Its wording briefly reads as follows:
passing an electric current in one direction through two conductors parallel to each other leads to their repulsion. Passing it in different directions, all other things being equal, causes the mutual attraction of two conductors.
In addition to these conclusions, visible to the naked eye, Ampere's Law includes a number of concepts that were discovered by the same researcher at the same time.
Having concluded that the behavior of two conductors when passing current through them in different directions, the French scientist began to study the forces that ensure their such behavior. The logic of his reasoning was simple: an electric current passed through a conductor creates a magnetic field. Figuratively, it can be represented as concentric circles framing a section of a conductor. Another conductor, provided that it is parallel to the first and the distance between them is small, falls into the area of the magnetic field, resulting in the formation of a force acting on the atoms of the conductor and setting them in motion. Ampere's law also allows us to explain the observations that have occurred:
- The magnetic field is the result of the flow of any electric current;
- A magnetic field affects moving electric charges.
Based on the experiment and the results obtained, Andre Ampère related the forces and phenomena that act on the conductors at the moment the electric current passes through them, so Ampere’s Law can be represented by the formula:
F = IBl sin a .
Where F is the Ampere force, i.e. force acting on a current conductor in a magnetic field;
I is the current strength;
l is the length of the conductor;
B is the magnetic induction vector module;
sin a is the sine of the angle formed between the magnetic induction vector and the conductor.
Ampere force is a vector quantity, i.e. having direction. You can define it using the so-called "Left Hand Rules" :
- four fingers of the left hand are directed in the direction of the flow of electric current, the magnetic induction vector (B) thus enters the palm perpendicularly. Then the direction of the current strength will indicate the thumb bent in the palm plane.
In modern science, the application of the Ampere Law mainly falls on the production of electrical engineering. In particular, we are talking about loudspeakers and speakers. The principle of operation of a loudspeaker, for example, is the conversion of electrical energy into acoustic energy. The coil - the basis of any speaker or loudspeaker - passes an alternating current through itself , the frequency of which corresponds to the frequency of the microphone or speaker. As the Ampere Law states, the coil begins to oscillate under the influence of current, the oscillations are transmitted parallel to the axis of the speaker and the diaphragm of the device. As a result, sound waves are emitted, which we hear.
In addition to creating the Law of Ampere, the inventor is known for having left his name in physics for centuries, since it was assigned to a unit of measurement of current strength.