Copper generates a weak repulsive force when exposed to a magnetic field due to its induced magnetic properties. The strength of the magnetic field required to produce a significant repulsive force on copper depends on various factors, including the field's intensity and the copper's dimensions. While there is no simple formula universally applicable, the relationship can be explored through principles of electromagnetic induction and Lorentz force. Understanding these interactions can help in calculating the repulsive force generated by different strengths of electromagnets. The discussion highlights the complexities involved in quantifying the effects of magnetic fields on conductive materials like copper.