Magnetic Field - Definition, Formula, Diagram, Properties, FAQs

Edited By Vishal kumar | Updated on Nov 26, 2024 09:32 AM IST

If you put a small magnet near a paper clip, the clips start attracting towards the magnets even if the magnet is not touching the clips. This happens due to the magnetic field. A magnetic field is the invisible region around a magnet where its force can be felt. It has both strength and direction, represented by magnetic field lines, which show the path a magnetic force follows. Let's explore this concept in detail in the below article.

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This Story also Contains

What is a Magnetic field?
What are Magnetic Field Lines?
Magnetic field Strength
How is Magnetic Field Created?
Properties of Magnetic Field Lines

Magnetic Field - Definition, Formula, Diagram, Properties, FAQs

What is a Magnetic field?

Magnetic fields are defined as the area around a magnet where the influence of the magnet can be felt. It has both magnitude and direction, and the magnetic field, as well as its field and direction, are represented by magnetic field lines.

S.I. Unit of Magnetic field is Tesla (T). and it is represented by B.

Magnetic field

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What are Magnetic Field Lines?

Magnetic field lines are imaginary lines that encircle a magnet. The density of a field's line indicates its magnitude. The magnetic field is strongest around the Poles of a magnet and weakens as it goes away from the poles.

Experiment to Observe Magnetic Field

A simple experiment can help to clarify the concept of magnetic field lines. Fix a sheet of white paper to a table and centre it with a bar magnet. Iron filings should be sprinkled around the magnet. Tap the table gently. It can be seen that the iron filings align in a certain pattern that represents the magnet's field. When these patterns are well examined, it is possible to see that iron filings collect around the poles, but the concentration is lower in the region away from the poles.

Magnetic field Strength

Magnetic field strength, also known as magnetic intensity is the portion of a material's magnetic field that is caused by an external current and is not intrinsic to the material itself. It is denoted by the vector H and is measured in amperes per metre.

How is Magnetic Field Created?

A magnetic field can be produced not just by a magnet, but also by a moving charge or electric current. We are all aware that matter is made up of small bits known as atoms. An atom's nucleus is made up of protons and neutrons, with electrons orbiting around it. The magnetic field is created by the spinning and circling of protons and neutrons or the nucleus of an atom. The magnetic field's direction is determined by the orbit and spin directions.

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Properties of Magnetic Field Lines

1. Magnetic field lines never cross each other.

2. It follows the path with the least resistance between the opposing magnetic poles. A bar magnet's magnetic lines of force travel in closed loops from one pole to the other.

3. The density of the field lines decreases as they pass from the higher permeability region to the lower permeability region.

4. Lines travel from the south pole to the north pole within a material magnetic field, while in the air, they flow from the north pole to the south pole.

5. The density of the magnetic field varies with distance from the pole. Their density reduces as one moves away from the pole.

6. Because it has both magnitude and direction, the magnetic field is a vector quantity.

Properties of Earth's Magnetic Field

1. The magnetic field of the Earth is uniform.

2. The magnetic field strength at the earth's surface is about 10^-4 Tesla.

3. The earth's magnetic field extends up to a height of 5 times the radius of the earth.

Frequently Asked Questions (FAQs)

1. Why do the magnetic field lines matter?

For the following reasons, magnetic flow lines are important:

1. The magnetic field lines shall be lines in a magnetic field, whose tangent shall give direction at every location of the field, and their density shall give field magnitude.

2. They mark the magnetic field direction.

3. Intensity of the magnetic field varies on the number of lines.

4. The lines at the poles are higher, thus the magnetic field at the poles is more powerful.

5. The force of the magnetic field depends on the number of magnetic field lines in a certain location.

2. Where is the strongest magnetic field?

The magnetic field is stronger in the poles because the field lines are most concentrated there. Field lines also demonstrate what happens to the magnetic fields of two magnets when they attract or repel one another.

3. Does space contain magnetic fields?

Yes, space contains magnetic fields. The spiral arms of the Milky Way seem, on the basis of investigations of several pulsars and the polarisation of their radio waves, a very big organised magnetic field. Magnetic fields were observed in interstellar dust clouds. The fields are increased as these clouds collapse.

4. What impacts the magnetic field strength of electromagnets?

Factors that affect the strength of an electromagnet's magnetic field: Factors that influence electromagnet strength are the nature of the core material, the current strength of the core, the number of turns on the centre, and the shape and size of the core.

5. How does shape influence the magnetic field?

A magnet's form has an impact on its force. If there is a pointing end of a magnet, it is stronger than the remainder of the magnet. It's because the form impacts the magnetic energy distribution in the region it occupies.