Correct option is C
Skin effect is more pronounced in AC supply:
Explanation: Skin effect is a phenomenon that occurs in alternating current (AC) systems, where the current flows primarily on the outer surface of a conductor. This is due to the back emf produced by the self induced magnetic flux in a conductor. For a DC current, the rate of change of flux is zero, so there is no back emf.
Effect of frequency: The skin effect increases with the frequency of the AC signal. As the frequency increases, the conduction begins to move the conductor cross-section to the surface only.
Effect of permeability: The skin effect increases with the increase in the permeability of the material.
