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Question
A permanent magnet in the shape of a thin cylinder of length 10 cm has M = 106 A/m. Calculate the magnetisation current IM.
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Solution
According to the problem, M (intensity of magnetisation) = 106 A/m.
`l`(length) = 10 cm = 10 × 10–2 m = 0.1 m
And IM = magnetisation current
Here we know that M = `I_M/l`
⇒ IM = M x `l`
= 106 × 0.1 = 105 A
Important point: Here, M = Intensity of magnetisation as its units are given as A/m.
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