Final answer:
Skin effect in electromagnetism refers to the concentration of alternating current near the surface of a conductor. To minimize its effects, the ferromagnetic envelope should be bonded at both ends of the conductor.
Step-by-step explanation:
In electromagnetism, skin effect refers to the tendency of alternating current to be concentrated near the surface of a conductor, rather than uniformly distributed. It occurs primarily due to the self-inductance of the conductor, which causes the magnetic field within the conductor to oppose the changing current and concentrate it near the surface. To minimize the negative effects of skin effect, the ferromagnetic envelope should be bonded at both ends of the conductor.