When a conductor is carrying AC current, the current is not distributed in the conductor uniformly. Rather it has tendency to concentrate near the surface of the conductor. What is this effect known as?

When a conductor is carrying AC current, the current is not distributed in the conductor uniformly. Rather it has tendency to concentrate near the surface of the conductor. What is this effect known as? Correct Answer Skin effect

Skin effect:

• Skin effect is the tendency of an alternating electric current to become distributed within a conductor such that the current density is largest near the surface of the conductor and decreases with greater depths in the conductor.
• The phenomenon arising due to unequal distribution of current over the entire cross-section of the conductor is referred to as the skin effect.
• Such a phenomenon does not have much role to play in the case of a very short transmission line, but with an increase in the effective length of the conductors, skin effect increases considerably.
• The distribution of current over the entire cross-section of the conductor is quite uniform in the case of a DC system.
• But in the alternating current system, current tends to flow with higher density through the surface of the conductors (i.e., the skin of the conductor), leaving the core deprived of current.

Hence due to the skin effect effective area of the conductor of the line decreases, so that the resistance of the line increases.

Factors affecting skin effect in transmission lines are:

• Frequency – The skin effect increases with the increase in frequency.
• Diameter – It increases with the increase in the diameter of the conductor.
• 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.
• Type of material – Skin effect increase with the increase in the permeability of the material (Permeability is the ability of the material to support the formation of the magnetic field).