09 January 2011

Electrical Interview Questions: Transmission and Distribution (Set 1)

What Is Skin Effect?
Answer: The Phenomenon of Concentration of an electric current near the surface of the Conductor is known as Skin Effect.
What Factors does Skin Effect Depend?
Answer: Skin Effect depends on the type of the material, frequency of the current, diameter of the Conductor, and shape of the Conductor. Skin Effect Increases with the Increase in the supply frequency, cross section of the Conductor, and permeability.
What is proximity Effect?

Answer: The Current Distribution (variation of Inductance)  in a conductor is effected by the presence of other conductors in the near vicinity of the conductor. This effect is called Proximity Effect
What Factors does Proximity Effect Depends?
Answer: Like Skin Effect Proximity Effect also depends on the Conductor Size, Frequency of the supply, resistivity and relative permeability of the material.Proximity Effect is more in the case of Large Conductors, high frequencies and Close Proximity between the Conductors.
What is meant by Transposition of the line conductors?
Answer: Transposition of line conductors means changing the position of the three phases on the line supports twice over the total length of the line. The line conductors in practice are so transposed that each of the three possible arrangements of conductors exist for one third of the total length of the line.


1 comment:

Venkatesh said...

This is very good and useful....thank u