Transmission Line Constants Interview Questions:

Following are the below Transmission Line Constants Interview Questions and Important Questions which is very useful for interviews and exams

1. Explain difference between skin effect and proximity effect.

2. Compare skin effect with proximity effect.

3. Distinguish between ac and dc resistances of a conductor. Why the two differ ? Derive an expression for internal flux leakage due to a single current carrying conductor.

4. Find out the flux linkage of single phase two-wire line and derive an expression for inductance per unit length.

5. Show that the inductance per unit length of an overhead line due to internal flux leakage is constant and is independent of size of conductor.

6. Derive an expression for inductance of a single-phase transmission line.

7. Define GMD and GMR. Explain the role of GMD and GMR in line inductance calculation.

8. Give the concept of ‘self GMD’. Derive an expression for inductance of an unsymmetrical, transposed line using solid round conductors.

9. Discuss the concept of geometric mean distance. How is this concept used to find the inductance of composite conductor line ?

10. Explain the terms geometrical mean distance (GMD) and `self GMD’ in the inductance calculation of single phase transmission lines with composite conductors. Find the self GMD of a conductor consisting of seven identical strands each having a radius r.

11. Starting from first principles, derive the expression for inductance of a 3-phase unsymmetrically spaced transposed transmission line.

12. Derive the expression of inductance for a 3-phase overhead line with symmetrical spacing.

13. Derive the expression for the inductance of a 3-phase line which is completely transposed.

14. Derive the expression for inductance of a 3Φ overhead line with unsymmetrical spacing.

15. Derive the expression of inductance of double circuit 3-phase line with conductors completely transposed.

16. Starting with flux linkage concept, find the inductance of 3-phase double circuit line with unsymmetrical spacing.

17. Explain the advantages of using bundled conductors in extra high collage transmission lines and the different configurations.

18. Derive expressions for line-to-line capacitance and line to neutral capacitance of a single-phase line.

19. Derive for the capacitance of 3-phase transmission line for symmetrical and unsymmetrical spacing.

20. Derive the expression for capacitance of a 3-phase overhead line with unsymmetrical spacing.

21. Derive formula to calculate the capacitance of a double circuit line. All the conductors are of equal diameter and are spaced hexagonally.

22. Explain with reasons :

• In double circuit lines the conductors constituting the same phase should be spaced as far away as possible and conductors of different phases should be spaced as close as possible.
• There is an increase in capacitance due to bundling of conductors.

23. Derive an expression for the capacitance per unit length of a 3-phase line completely transposed. What is the effect of earth on the capacitance of the line ?

24. Explain the method of images for the calculation of capacitance of a three phase transmission line.

25. Show that presence of earth increases capacitance of transmission lines.

26. What are the advantages of transposition of conductors ?

27. Discuss the transposition of conductors of a three-phase transmission line.

28. Explain briefly about the following :

• GMD.
• Bundled conductors.
• Double circuit lines.
• Transposition.

29. What is meant by transposition in an overhead line ? How and why it is carried out ?

30. Write short notes on the following :

• Skin effect.
• Proximity effect.
• Skin, proximity effects.
• GMR.
• Bundle conductors.
• Line transposition.
• Transposition of conductors.