A) \[MH\,\,(1-cos\theta )\]
B) \[\frac{M}{H}\,\,(1-cos\theta )\]
C) \[\frac{M}{H}\,\,(cos\theta -1)\]
D) \[MH\,\,(cos\theta -1)\]
Correct Answer: A
Solution :
Work done in rotating the magnet through \[\theta \] is\[W=\int_{0}^{\theta }{\tau \,\,d\,\,\theta =\int_{0}^{\theta }{MH\,\sin \,\theta \,d}\,\theta }\]\[=\,\,\,MH[-cos\theta )]_{0}^{\theta }\,\,=\,\,MH[1-cos\theta ]\]You need to login to perform this action.
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