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InterviewSolution
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Define magnetic susceptibility of a material. Name two elements one having positive susceptibility and other having negative susceptibility. |
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Answer» (1) Susceptibility : When a material is placed in a magnetic field, the ratio of the intensity of magnetization acquired by it to the intensity of the applied magnetic field is called its susceptibility. Suspectibility `chi = ("Intensity of magnetisation , I")/("Applied magnetic field, H")` (2) The susceptibility of a material represents its ability to get magnetism. (3) Susceptibility is a dimension less quantity. (4) Relation between `mu_(r)` and `chi` : (a) Suppose that material is placed in a magnetic field of intensity H. Ley I be the intensity of magnetisation acquired by it. (b) Then the magnetic induction with in the material is `B = mu_(0) H + mu_(0)I rArr (B)/(H) = mu_(0)[1+(I)/(H)]` `rArr mu = mu_(0)[1+ chi] rArr (mu)/(mu_(0)) = 1+chi` `:. mu_(r) = 1+ chi [because mu_(r) = (mu)/(mu_(0))]` (5) Negative susceptibility `(chi)` of diamagnetic elements are Bismuth `(-1.66 xx 10^(-5))` and copper `(-9.8 xx 10^(-6))`. (6) Positive susceptibility of Ferromagnetic elements are Aluminium `(2.3 xx 10^(-5))` and oxygen at STP `(2.1 xx 10^(-6))`. (7) Large and positive susceptibility of ferromagnetic elements are Cobalt and Nickel. |
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