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प्रश्न
Derive the relation between magnetic field intensity(H) and magnetization(M) for a magnetic material placed in a magnetic field.
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उत्तर
- Relation between magnetic field intensity(H) and magnetization(M):
a. Consider a magnetic material (rod) placed in a magnetizing field (solenoid with n turns per unit length and carrying current I).
b. The magnetic field inside the solenoid is given by,
B0 = μ0nI ….(1)
Where µ0 = permeability of free space.
c. The magnetic field inside the rod is given as,
Bm = µ0M ….(2)
Where M = magnetization of the material
d. The net magnetic field inside the rod is expressed as,
B = B0 + Bm ….(3)
∴ B = µ0nI + µ0M
∴ B = µ0H + µ0M
Where H = nI = Magnetic field intensity
∴ B = µ0 (H + M)
∴ H = `"B"/mu_0 - "M"` ….(4)
e. Equation (4) shows that the magnetic field (B) induced in the material depends on magnetic field intensity (H) and magnetization (M).
संबंधित प्रश्न
What is Magnetization?
State formula and S.I. unit of Magnetization.
Which of the following pairs has quantities of the same dimensions?
(a) Magnetic field B and magnetising field intensity H
(b) Magnetic field B and intensity of magnetisation I
(c) Magnetising field intensity H and intensity of magnetisation I
(d) Longitudinal strain and magnetic susceptibility
Mark out the correct options.
(a) Diamagnetism occurs in all materials.
(b) Diamagnetism results from the partial alignment of permanent magnetic moment.
(c) The magnetising field intensity, H, is always zero in free space.
(d) The magnetic field of induced magnetic moment is opposite the applied field.
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Assertion: Susceptibility is defined as the ratio of intensity of magnetisation I to magnetic intensity H.
Reason: Greater the value of susceptibility, smaller the value of intensity of magnetisation I.
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Magnetization of a sample is ______.
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Magnetic intensity is given by ______.
Magnetic lines of force due to a bar magnet do not intersect because ______.
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Magnetic permeability is maximum for ______
What are the dimensions of χ, the magnetic susceptibility? Consider an H-atom. Guess an expression for χ, upto a constant by constructing a quantity of dimensions of χ, out of parameters of the atom: e, m, v, R and µ0. Here, m is the electronic mass, v is electronic velocity, R is Bohr radius. Estimate the number so obtained and compare with the value of |χ| ~ 10–5 for many solid materials.
Define magnetization.
An example of a perfect diamagnet is a superconductor. This implies that when a superconductor is put in a magnetic field of intensity B, the magnetic field B inside the superconductor will be such that ______.
A bar magnet has length 3 cm, cross-sectional area 2 cm3 and magnetic moment 3 Am2. The intensity of magnetisation of bar magnet is ______.
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State SI unit of Magnetization.
What is the net effect of magnetic dipoles in random orientation?
Which expression defines magnetisation?
Which expression relates magnetic induction or flux density to magnetic intensity and magnetisation?
What is the SI unit of magnetic permeability?
Which expression gives the magnetic induction of a solenoid core using relative permeability?
Why are soft ferromagnetic materials used in transformer cores?
Why are hard magnetic materials chosen for permanent magnets?
