What is Magnetic Susceptibility - Formula, Definition, Unit, FAQs

Edited By Vishal kumar | Updated on Sep 24, 2024 05:44 PM IST

Here, in this article, we will discuss susceptible meaning, magnetic susceptibility, magnetic susceptibility formula, unit of magnetic susceptibility, what is magnetic substance, susceptibility of diamagnetic material, ferromagnetic material, diamagnetic material etc.

Susceptible meaning

The literal meaning of the word Susceptible in English is to be influenced or receptive to. Susceptible meaning in Hindi is अतिसंवेदनशील.

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What is magnetic susceptibility?

The magnetic susceptibility of a magnetic substance is defined as the ratio of the intensity of magnetization to the magnetic intensity.

Magnetic Susceptibility Formula

The magnetic Susceptibility Formula is given by, X_m

Where,

I is intensity of magnetization

H is magnetic intensity

The magnetic susceptibility of a magnetic substance gives the measure of its aptness to acquire magnetism. As magnetic susceptibility is the ratio of the two quantities having same units ()it has no units.

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What is Magnetic Susceptibility - Formula, Definition, Unit, FAQs

Magnetic materials

On the basis of magnetic behaviour of different magnetic materials, Faraday divided the magnetic materials into three classes:-

1. Diamagnetic:- The substances, which are placed in a magnetic field are feebly magnetized in a direction opposite to that of the magnetizing field, are called diamagnetic substances.

When we place a diamagnetic substance inside an external magnetic field, the magnetic field inside the diamagnetic field is found to be slightly less than the external magnetic field. It is also noticed that if a diamagnetic sample is placed inside a non-uniform magnetic field, then it tends to move from the stronger part to the weaker part of the magnetic field. It may be pointed out that the diamagnetic effects are too feeble to be detected, unless the applied magnetic field is strong. Some of the few examples of diamagnetic substances are copper, zinc, bismuth, silver, gold, lead, glass, marble, water, helium, etc.

The magnetic susceptibility of a diamagnetic substance has a small negative value. Since, for a diamagnetic substance, ‘I’ has a small negative value, from the relation

It follows that will have a small negative value. It is of the order of to (negative).

The susceptibility of a diamagnetic substance does not change with temperature for practical purposes. However, bismuth at low temperature is an exception.

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2. Paramagnetic:- The substances, which are placed in a magnetic field are feebly magnetized in the direction of the magnetizing field, are called paramagnetic substances.

When a paramagnetic substance is placed inside an external magnetic field, the magnetic field inside the paramagnetic field is found to be slightly greater than the external magnetic field. A paramagnetic substance tends to move from the weaker part of the magnetic field to stronger part, when placed in a non-uniform magnetic field. The paramagnetic effects are perceptible only when a strong magnetic field is there. Some of the few examples of paramagnetic substances are aluminum, sodium, antimony, platinum, copper chloride, liquid oxygen etc.

The magnetic susceptibility of paramagnetic substances has a small positive value. Since, for a paramagnetic substance, ‘I’ has a small positive value, from the relation, it follows that will have a small positive value. It is of the order of to.

The susceptibility of paramagnetic substances is inversely proportional to its absolute temperature.

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3. Ferromagnetic:- Those substances, when placed in a magnetic field are strongly magnetized in the direction of the magnetizing field, are called ferromagnetic substances.

When a ferromagnetic substance is placed inside an external magnetic field, the magnetic field inside the ferromagnetic field is found to be greatly enhanced than the external magnetic field. As a result, when a ferromagnetic substance is placed in a non-uniform magnetic field, it quickly moves from the weaker part to the stronger part of the magnetic field. In other words, the ferromagnetic effects are perceptible even in the presence of a weak magnetic field. Some of the few examples of ferromagnetic substances are iron, nickel, cobalt, alnico etc.

The magnetic susceptibility of ferromagnetic substances have a large positive value. It follows from the relation. It is of the order of several thousand. The susceptibility of ferromagnetic substances decreases with the rise of temperature.

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Frequently Asked Questions (FAQs)

1. If a diamagnetic substance is brought near north or South Pole of a bar magnet, it is

a) attracted by both the poles.

b) repelled by both the poles.

c) attracted by the north pole and repelled by the south pole.

d) repelled by the north pole and attracted by the south pole.

Option (b) is correct. The diamagnetic substances are feebly repelled by a magnet.

2. In which type of magnetic material the magnetic susceptibility does not depend on temperature?

The magnetic susceptibility in case of a diamagnetic material does not depend on temperature.

3. Why is diamagnetism, in contrast, almost independent of temperature?

The atoms of a diamagnetic do not have intrinsic magnetic dipole moment. While placing a diamagnetic sample in a magnetic field, the magnetic moment of the sample is always opposite to the direction of the field. It is not affected by the thermal motion of the dipoles.