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The image shows two inventions with opposite roles, which combine perfectly with the effect produced, respectively, on the left is illustrated Faraday’s cage, struck by the very high voltage electric current produced by the Tesla coil on the right.

Faraday’s cage, an invention of the English physicist Michael Faraday, has the role of protecting its interior from the outside electric and magnetic field, so a person inside the cage, as shown in the pictures, can not be harmed by the electric current from outside.

The cage is highlighted by a vertical rectangle, outlined with a thick line, representing metal beams, connected between them by an electrically conductive metal mesh, which cover the enclosure, the mesh being rendered by grid texture.

In the center of the cage is a man standing, marked embossed.

The upper right corner of the Faraday cage is struck by the electric current that passes with a very high frequency, being visible and resonating strongly in the air.

The electric current is rendered by thick, wavy and curved lines, slightly broken and sharp towards the ends, branched in three parts, located on the top center.

The Tesla coil, which produces such electricity of extremely high frequency and voltage such as lightning, and which has extremely strong electromagnetic fields that may be seen and heard, is illustrated on the right side in the shape of a hammer.

The high voltage end from which the electrical discharge of bolts of high sound resonance travels in the air, is rendered at the top of the coil, as a horizontal rectangle, with rounded ends, filled with the texture of horizontal and parallel lines.

It continues with the coil itself, formed by a cylindrical frame on which are wrapped copper wires, respectively electrical conductors.

It is marked by a vertical rectangle, narrow and embossed.

At its base is the transformer, highlighted by a square filled with dotted texture.

General information

These are two inventions that complement each other but have opposite roles. One is meant to produce electricity, and the other is to protect us from the effects of electricity.

The Tesla coil was invented by Nicola Tesla and is used to produce high frequency alternating current. 

The alternating current is the one whose direction changes periodically, in opposition to the continuous one, the direction of which remains unchanged. Frequency is the number of times the alternating current changes direction within a second and is measured in hertz.

The frequency of the alternating current we have at the sockets in our home changes direction 50 times per second, so it has a frequency of fifty hertz. The frequency of alternating current produced by Tesla coils is much higher and can reach thousands of hertz. A Tesla coil is an alternating current transformer that raises the voltage, but also the frequency. 

Tesla used these coils for experiments in public lighting, as well as in experimenting with wireless transmission of electricity. Nowadays, the use of the Tesla coil is limited to conducting experiments, but also to creating light and acoustic effects in some shows. With the help of the Tesla coil, artificial lightning can be created, with voltages of millions of volts. Artists are dressed in flexible steel suits that act as a Faraday cage that protects them from the effects of violent electrical discharges. The suit blocks the high voltage to the surface instead of allowing it to pass through it.

Faraday’s cage is a special enclosure that serves as protection against electrical and electromagnetic waves. It was invented by Michael Faraday, which is why it is named after him. It is a confined space on all sides, surrounded by a metal wire conducting electricity. An electric field outside the Faraday cage produces a discharge on the conductive surface, and inside the cage is another field, which neutralizes the external one. 

Examples of things that act like Faraday cages are the cars and the airplanes. Even if the car or plane is struck by lightning, passengers are safe because the electric field outside cannot penetrate the enclosure.

Did you know that a microwave oven is a Faraday cage? From inside, the electromagnetic waves that heat the food cannot get outside. If they were not blocked inside, they would have devastating effects on people’s health. 

The easiest way to experience the effect of the Faraday cage is by perfectly wrapping a mobile phone in an aluminum foil. If we call the phone wrapped in tinfoil, we will be notified that the subscriber is unavailable. This is because the metal foil blocks the penetration of the mobile network signal inside. For the experiment to be successful, several layers of metal foil can be used.

Bibliography

  1. https://despretot.info/cusca-faraday-definitie/
  2. https://evz.ro/bega-2019-the-lightning-project-cavaleri-se-lupta-cu-fulgere-reale-de-5-m-i-galerie-foto-video.html
  3. https://ro.wikipedia.org/wiki/Bobin%C4%83_Tesla
  4. https://destepti.ro/ce-este-cusca-lui-faraday

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