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Question
Derive the relation between magnetic field intensity(H) and magnetization(M) for a magnetic material placed in a magnetic field.
Solution
- 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).
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