# Physics Course/Magnet/ElectroMagnet
## ElectroMagnet Introduction

It's been observed that Current carrying conductor does exhibit a Magnet's characteristic

## ElectroMagnet

The magnetic field of Earth and the planets is explained as ElectroMagnet by my own theory. The magnetic field of the Earth and the planets is generated by electric currents. But, all published theories to explain the magnetic field of a planet are wrong. There is no known theory able to explain the obvious connection with the rotation, including why the direction of rotation and field approximately match. The rotation of the planet is obviously the cause of the magnetic field. Popular theory not even explain the polarity of the field. Despite the lack of evidence, outlandish theories about the magnetic pole reversals are common. In fact, the polarity is clear from the rotation and can therefore cannot change. The correct explanation is actually surprisingly easy. The cause is simply the electric current generated directly by the rotation of the planets, and the charge separation of free ions by gravity. Positively charged ions are usually heavier than negative charged ions and are therefore shifted to the rotation axis. We first consider only the negative charges, the electrons, of the Earth, neglecting the positive charges of the atomic nuclei. In 24 hours the total charge of the electrons crosses once through a cross section of the Earth. The mass of the Earth is at first approximation two times the mass of the protons, since there are about as many neutrons almost as heavy. Then the current caused by the rotation of the electrons around the axis of the Earth within 24 hours is easy to calculate. $\left({\frac {mass\,of\,Earth}{2\times mass\,of\,proton}}\right)\times \left({\frac {charge\,of\,electron}{24h}}\right)=-3.3\times {10}^{27}\,A$ Since the Earth is electrically neutral overall, a current of exactly equal magnitude is produced by positive charges. The magnetic fields generated by both currents cancel each other almost completely. But, since the positively charged ions, however, are slightly shifted by gravity towards Earth's axis, the remaining effect of the negative charges causes Earth's magnetic field.
It's been observed that
* Any Coil conductor when conducts current does attract metal just like the Lodestone Magnet . Hencr the name ElectroMagnet . Current carrying conductor does exhibit the characteristic of a magnet
* When place a metal material in the turns of current conducting Coil of several turns the material become a magnet . Unlike ElectroMagnet, when the current is turn off or when the material is taken out of the coil's turns the material still retain its magnetic hence the name Permanent Magnet

## ElectroMagnet Characteristics

* Magnetic field
    The Magnetic field is made up of Magnetic field lines that travels from North Pole to South Pole that is from Positive terminal to the Negative terminal . When current is zero, ElectroMagnet does not attract metal or Magnetic field does not exist when there is no current flow . The Magetic Field Strength is the product of The Coil's Inductance and Current .
    B = L I
* Magnetic Poles
    A magnet has two "Poles" namely North Pole and South Pole correspond to the Current Polarities . North Pole correspond to Plus polarity . South Pole correspond to Minus polarity