# Magnetic Field

## Magnetic field:

Magnetic field is a field which is produced by permanent magnets and artificial magnets. But in permanent magnets generates magnetic field Naturally, but in artificial magnets produces the magnetic field due to flow of charges (Current). A magnetic field is a vector field that describes the magnetic influence of electrical currents and magnetized materials. Magnetic field is a field of force and it does not require any medium to transmit. In your everyday life, the effects of magnetic fields are most readily encountered with nearby permanent magnets, which pull on magnetic materials (such as iron) and attract or repel other magnets.

Example for permanent magnet: The Earth has natural magnetism, Because the core of our planet is filled with molten iron (Fe), there is a large field that protects the Earth from space radiation and particles such as the solar wind. But, The Earth has a huge magnetic field. When you look at tiny magnets, they are working in a similar way. The magnet has a field around it, these magnets are made up of steel, Nicol, etc

In the earth, Neodymium is the strongest permanent magnet in the world.

Note: Magnetic field is not related with gravity, gravity is different and the magnetic field is different. The amount of gravity is based on an object’s mass, while magnetic strength is based on the material that the object is made of.

Example for the Artificial magnetic field:

• An inductor is the best example for creating the artificial magnetic field. Inductor stores the electrical energy and releases the energy in terms of magnetic field. All over the world, the artificial magnets are produced by electromagnetic inductive coils. Which produce the magnetic field when an electric current passes through the coil. Magnetic field can be predicted by iron filings. The energy storing capacity of the magnetic field is higher than the electric field, this distinguishes magnetic field from the electric field, and therefore it is utilized in almost every electromechanical device like transformers, motors, and generators.
• Take an electromechanical device (Converts electrical energy to mechanical energy or mechanical energy to electrical energy) i.e A Motor: the principle of motor is, when current carrying a conductor is kept in a magnetic field which experiences a force. We get the force in terms of torque. The developed torque is equal to ….in Mathematical Expression Torque= Force*distance

Note: A magnetic field is generated when electric charge carriers such as electrons move through space or within an electrical conductor, and moving charges are affected by magnets. But in Stationary charges, do not produce such magnetic fields, and are not affected by magnets. If a circuit is an open circuit, then the magnetic field also zero… because the current in the open circuit is equal to zero.

## History:

The magnetic field was examined by Michael Faraday and later by James Clerk Maxwell.

Magnetic field lines are having own properties as like Electric field

### Magnetic Field lines properties:

• Magnetic Field lines attempt to form closed loops from pole to pole. These lines are not discontinuous as of electric field
• They never intersect each other.
• The field starts from South Pole and ends in north pole (within the body)
• Outside the body of magnetic direction of lines is from the North Pole to South Pole (outside of the body)
• Tangent to field line at any point gives the direction of magnetic field at that point.
• Their strength decreases with increasing distance from the poles. The strength of field can be varied in accordance with the amount of current flowing in the conductor around the coil.
• Unlike poles attract (North and South), Same Poles (North & North or South & South)
• Field lines are high concentrate in Pole corner side and low concentration in the center of the body.
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## Explanation for Attraction and repulsion property:

The magnetic field has the same property as the electric field. In the electric field, you know about charged particles. It is nothing but positive and negative charges, both have a property unlike charges are attracted (positive charges are attracted to negative charges) and like charges repel each other (positive charges & positive charges or –Ve charges & – Ve charges have rebelled each other). Two wires, with current flowing, when placed next to each other, may attract or repel like two magnets. It all has to do with moving charges.