A magnet is a material or object that produces magnetic field.

This magnetic field is invisible and causes the most notable property of a magnet: a force that pulls on nearby magnetic materials, or attracts or repels other magnets.

There are 2 kind of magnet - Hard or Permanent Magnet

and- Soft or Impermanent Magnet

Paramagnetic ( can be attracted ) Eg. Liquid Oxygen Diamagnetic ( repelled )

Eg. Graphite Ferromagnetic ( retain their own

magnetization )Eg. A traditional refrigerator magnet

Ferrimagnetic retain their magnetization in the absence of a field.

However, like antiferromagnets, neighboring pairs of electron spins like to point in opposite directions.

In an antiferromagnet there is a tendency for the intrinsic magnetic moments to point in opposite directions.

When all atoms are arranged in a substance so that each neighbor is anti aligned, this is called antiferromagnetism

As you see in the left side, that is Magnetic recording Media

Credit, debit, ATM Electric Motors Compasses MagLev Trains Speakers And Microphones

•A solenoid is a three-dimensional coil.• In physics, the term solenoid refers to a loop of wire, often wrapped around a metallic core, which produces a magnetic field when an electric current is passed through it. •Solenoids are important because they can create controlled magnetic fields and can be used as electromagnets.

Heating a magnet past its Curie point Contact through stroking one magnet

with another in random fashion Hammering or jarring Being placed in a solenoid which has

an alternating current

Calculating the attractive or repulsive force between two magnets is, in the general case, an extremely complex operation, as it depends on the shape, magnetization, orientation and separation of the magnets.

› F is force (SI unit: newton)› qm1 and qm2 are the magnitudes of magnetic poles (SI unit: ampere meter)

› μ is the permeability of the intervening medium (SI unit: tesla meter per ampere, henry per meter or newton per ampere

squared)› r is the separation (SI unit: meter).

Maglev is a type of high-speed train that hovers over the track and uses electromagnets to propel it along the track. 

There are three basic components of the trains: a large electrical power source, metal coils lining the track, and large magnets attached underneath the train.

Since the trains do not actually touch the track, there is no friction present, which  enables the train to reach speeds of approximately 300 mph. 

This also reduces the noise and vibrations common on other types of similar transportation. 

1. Electrodynamic Suspension System2. Electromagnetic Suspension System

The electrodynamic system, also known as the Linear express, was developed in Japan.

The electrodynamic system is based on three basic principles, Lenz's law (motional emf), moving current creates a magnetic field, and that like poles of a magnetic field repel while opposite poles attract.

Superconducting wires are used to create the electromagnets on the train with a linear synchronous motor that provides the alternating current.

The three forces allowing the train to move and hover over the track are propulsion, levitation, and guidance.

                                      Track of Linear Express train in a tunnel Linear Express train, model MLX01-901                                           

Trains levitate by electrodynamic suspension system levitate for 8-10 cm while the electromagnetic system only at 1-2cm above the track.

The levitation in the electrodynamic system depends upon induced currents caused by the movement of the train's electromagnets and the levitation coils on both sides of the track.

The propulsion coils in the track have an ac current that creates an opposite magnetic field to the electromagnet,.

Since opposite poles attract, the electromagnet pulls the train moves forward.

The Electromagnetic Induction Suspension System, also known as the Transrapid System was tested and developed in Germany.

The first test vehicle called the "Principle Vehicle" had a maximum velocity of 90 km/h and was developed in 1971 on a 600 meter track. 

Starting in 1972 Germany also developed and tested an Electrodynamic System (EDS) which could be considered the forefather of the Japanese EDS (Linear Express) which had a maximum velocity of 401.3km/h.

Characteristics

Electrodynamic suspension

Electromagnetic suspension

Other names Linear Express TransrapidCountry of

originJapan German

Magnets on track Electromagnets FerromagnetsMagnets on train Electromagnet-

superconductorsElectromagnet-controlled and

monitored

Dimensions 21.6x2.8x2.85m  

25.5x3.7x3.95m

Body Structure Aluminum alloy Aluminum alloyLevitation

systemStable, only

levitates at high speeds,

electromagnets on side train and null flux coils on

the track

Unstable, reason active control of

guidance system.

Electromagnets on bottom train

and ferromagnets on

track

Guidance system Non-contact magnetic repulsion based on Lenz's law

 

Active control using non-contact

magnetic attraction

Propulsion system Electromagnets on train and side of track, alternating current changes

polarity, used to repel and attract train

forward.

Electromagnets on side of the train and

ferromagnets, electromagnets use alternating current