Correct Answer - Option 3 : High
The non-uniform distribution of electric current over the surface of the conductor is called the skin effect.
In the skin effect, the concentration of charge is more near the surface as compared to the core of the conductor which causes the increase in ohmic resistance of the conductor.
Factors affecting the Skin effect:
Skin effect increases with the increase in frequency.
At low frequencies, such as 50Hz, there is a small increase in the current density near the surface of the conductor.
At high frequencies, such as radio-frequency, practically the whole of the currents flows on the surface of the conductor, and the Skin effect is more noticeable at high frequencies.
With DC supply (frequency is zero), the current passed in a conductor is uniformly distributed over the cross-section of the conductors.
Skin effect increases with the increase in diameter of the conductor.
3. The shape of the conductor:
Skin effect is more in the solid conductor and less in the stranded conductor because the surface area of the solid conductor is more.
4. Type of material:
Skin effect increase with the increase in the permeability of the material.