Important Questions of Electrical Design of Overhead Lines:
1. What do you understand by the constants of an overhead transmission line ?
2. What is skin effect ? Why is it absent in the d.c. system ?
3. Find an expression for the flux linkages
(i) due to a single current carrying conductor
(ii) in parallel current carrying conductors
4. Derive an expression for the loop inductance of a single phase line.
5. Derive an expression for the inductance per phase for a 3-phase overhead transmission line when
(i) conductors are symmetrically placed
(ii) conductors are unsymmetrically placed but the line is completely transposed
6. What do you understand by electric potential ? Derive an expression for electric potential
(i) at a charged single conductor
(ii) at a conductor in a group of charged conductors
7. Derive an expression for the capacitance of a single phase overhead transmission line.
8. Deduce an expression for line to neutral capacitance for a 3-phase overhead transmission line when the conductors are
(i) symmetrically placed
(ii) unsymmetrically placed but transposed
9. What is the effect of unsymmetrical spacing of conductors in a 3-phase transmission line ?
10. Will capacitance of a transmission line depend upon the ground effect ?
11. Why do we find line to neutral capacitance in a 3-phase system ?
12. How does skin effect vary with conductor material ?
13. What is proximity effect ?