Force On Magnetic Dipole In Non Uniform Field — the NEET Physics formula with its derivation, variables, validity constraints and worked solver.
Force on Magnetic Dipole in Non-Uniform Field This formula describes the net force acting on a magnetic dipole moment ( ) when it is placed in a spatially varying (non-uniform) magnetic field ( B ). The potential energy ( U ) of a magnetic dipole in a field B is given by U = - B . The net force ( F net ) is derived from the negative gradient of the potential energy: F net = - U . Substituting the potential energy yields F net = ( B ) . Using vector calculus identities, this gradient operation simplifies to the form F net = ( ) B . The magnetic field must be non-uniform (i.e., B 0 ). The dipole moment is assumed to be constant over the region of interest. Confusing this force with the force in a uniform field ( F = B ), which is incorrect unless the field is uniform. Assuming the force is zero just because the dipole is aligned with the field ( B ); the force is zero only if the field is uniform. Misunderstanding the gradient operator ( ) and treating the relationship as a simple dot product.