The fact that a conductor carries more current on the surface as compared to core is Known as
(A) Skin effect
(B) Corona
(C) Permeability
(D) Unsymmetrical Fault
Ans: (A) Skin effect
Explanation:
When alternating current flows through a conductor it is always linked with flux. The flux linking the central portion of the conductor is always more than that at the surface.
This results in higher current density at the surface of the conductor as compared to that at the core of the conductor.
This has following effects.
1. Skin Effect causes increase in DC resistance of the effective DC resistance.
2. Skin effect is high for conductors of magnetic materials.
3. Skin effect is more predominant at higher frequencies.
4. In case of DC, Skin effect does not exist.
More MCQ on Skin effect
1. Skin effect results in
(A) Reduced effective resistance but increased effective internal reactance of the conductor
(B) Increased effective resistance but reduced effective internal reactance of the conductor
(C) Reduced effective resiatance as well as effective internal reactance
(D) Increased effective resistance as well as effective internal reactance.
Ans: (B) Increased effective resistance but reduced effective internal reactance of the conductor
2. Skin effect depends on
(A) Size of the conductor
(B) Frequency of the current
(C) Resistivity of the conductor material
(D) All of the above
Ans: (D) All of the above
3. The skin effect of a conductor will reduce as the
(A) Diameter increase
(B) Frequency increases
(C) Resistivity of conductor material increases
(D) Resistivity of conductor material increases
Ans: (D) Resistivity of conductor material increases
4. Skin effect is proportional to
(A) Diameter of conductor
(B) Square of (Diameter of conductor)
(C) (Diameter of conductor)3
(D) (Diameter of conductor)4
Ans: (B) Square of (Diameter of conductor)
