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Question
Will a current loop placed in a magnetic field always experience a zero force?
Solution
No, it depend on the magnetic field, i.e. whether the field is a uniform or a non-uniform magnetic field and also on the orientation of the current loop. In case of a uniform magnetic field, the force on the circular loop is zero if the magnetic field is parallel to the plane of the loop and in case of a non-uniform magnetic field, the force may or may not be zero.
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