Correct Answer - Option 3 : Larger than unity
Ferromagnetic Substances: The substances which are strongly magnetized when placed in an external magnetic field in the same direction to the applied field are called ferromagnetic substances.
Example: Iron, nickel, cobalt
Properties:
- These are characterized by parallel alignment of magnetic dipoles
- These substances are strongly attracted by a magnet
- It develops strong magnetization in the direction of the applied magnetic field
- By removing the magnetizing filed, it does not lose its magnetization
- When placed in a non-uniform magnetic field, it tends to move from weaker to stronger regions of the magnetic field
- When placed in a uniform magnetic field, it aligns itself parallel to the direction of the magnetic field
- Magnetic susceptibility is much greater than 1 i.e. more than 100
- Relative permeability is much greater than 1 i.e. more than 100
- Magnetic permeability is much larger compared to free space
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Material
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Magnetic Susceptibility (Xm)
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Relative Permeability
(Km = 1 + Xm)
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Magnetic Permeability
(μm = Kmμ0)
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Diamagnetic
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-10-5 to -10-9
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< 1
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μm < μ0
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Paramagnetic
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10-5 to 10-3
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> 1
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μm > μ0
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Ferromagnetic
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≫ 1 (i.e. >100)
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≫ 1 (i.e. >100)
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μm ≫ μ0
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