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Question
Find the magnetization of a bar magnet of length 10 cm and cross-sectional area 4 cm2, if the magnetic moment is 2 Am2.
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Solution
Given:
Mnet = 2 Am2, l = 10 cm = 10 x 10–2 m,
area of cross section =4 cm2 = 4 x 10–4 m2
To find:
magnetisation (MZ)
`M_z=M_"net"/V`
`V=lxx""cross sectional area`
`=(10xx10^-2xx4xx10^-4)`
`=4xx10^-5m^3`
From formula,
`M_z=2/(4xx10^-5)`
`M_z=50000 A/m`
The intensity of magnetisation is 50000 A/m.
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