Magnetic Elements

Introduction

Magnetic Elements are free-floating magnetic needles that come to rest roughly around the geographical north-south axis. This behaviour demonstrates that the Earth operates as a massive magnetic dipole; its magnetic poles lie close to its geographical ones.

Because the magnetic needle’s north pole approximates geographic north (NG), the magnetic pole near it is the magnetic south pole of Earth (Sm). In addition, the pole near the geographic south (SG) is the Earth’s magnetic north pole (Nm).

• The magnetic variation is also known as declination 𝛳
• δ represents the dip or inclination
• B_h denotes the horizontal component of the Earth’s magnetic field

Magnetic Fields: A Brief Description

The magnet affects the area of its location. That is why when we place iron filings around the magnet, its force arranges them in a pattern.

• The earth’s magnetic field is similar to that of a bar magnet that has been inclined 11 degrees from the earth’s axis of rotation. The problem with this picture is that the Curie temperature of iron is around 770 C. The core of the planet is hotter and therefore not like that. The question is then, how did the earth get its magnetic field? 
• The magnitude varies over the earth’s surface from 0.3 to 0.6 gauss. Rock samples of different ages in similar locations show different directions of permanent magnetisation. 
• Although the details of the dynamo effect are not fully known, the earth’s rotation plays a role in creating the currents believed to be the source of the magnetic field. The Mariner 2 spacecraft found that Venus has no such effect even though the planet’s main iron content should be similar to the earth’s magnetic field. The rotation period of Venus of 243 earth days is too slow to produce the dynamo effect.
• As a result, we can assume that the field lines originate from the north pole and combine at the south pole.
• The field lines inside the magnetic field run from the south pole to the north pole. Magnetic field lines are hence closed curves.
• The degree of closeness of the field lines indicates the relative intensity of the magnetic field.
• There are no field lines that intersect one another.

Magnetic Susceptibility Formula

The ratio of the magnetisation M within the material to the applied magnetic field strength H, or m = M/H, is the magnetic susceptibility formula of a material, typically indicated by m. The absolute temperature is inversely related to paramagnetic susceptibility.

We can classify the magnet into three categories:

• Permanent magnet: A magnet made of a permanently magnetised substance that generates its own continuous magnetic field is a permanent magnet. Magnetisable materials are also called ferromagnetic. Materials like iron, nickel, and cobalt are examples.
• Temporary magnet: A magnet that exhibits magnetism for a limited time is known as a temporary magnet. These magnets often comprise soft materials with low magnetic characteristics. They become magnetised for a brief time when a strong or permanent magnet attracts them.
• Electromagnet: It is a magnet that generates a magnetic field due to current passing through it. Wire twisted into a coil is the most common electromagnet; as current travels through the wire, a magnetic field forms inside the coil. When you turn off the current, magnetism disappears. Electromagnets are usually parts of motors, generators, and hard disc drives.

Three Elements of the Earth’s Magnetic Field

The size, as well as the direction of the Earth’s magnetic field, are determined by three elements of the Earth’s magnetic field:

• Magnetic declination
• Magnetic inclination or the angle of dip
• The horizontal component of the Earth’s magnetic field

Magnetic Declination

Magnetic declination is the angle between the true north and the magnetic north. On the horizontal plane, true north is never in the same place and varies based on the location on the Earth’s surface and the passage of time.

Magnetic Inclination

The angle of dip is another name for the magnetic inclination. It is the angle formed by the horizontal plane on the Earth’s surface. The magnetic equator has a 0° angle of dip, while the magnetic poles have a 90° angle of dip.

Horizontal Component of the Earth’s Magnetic Field

The horizontal component of the Earth’s magnetic field is zero. This location’s dip angle would be 900 degrees.

What is Magnetism?

Magnet has the property to repel or attract other substances, referred to as magnetism. When you position two bar magnets close to one another, the same poles will repel each other; however, the opposite poles will tend to attract. 

Conclusion 

The Earth’s magnetic field is believed to play an essential role in making the planet habitable. A magnetic field not only determines the direction of our compass needles but also acts as a kind of shield that deflects the solar wind that could otherwise destroy the air as we know it – the atmosphere. Therefore, the Earth’s magnetic fields are an essential topic of study and research in physics. The Earth’s magnetic field plays a part in making the planet hospitable to life. A magnetic field not only determines the direction of our compass needles but also acts as a kind of shield that deflects the solar wind that could otherwise devour the wind.