Q21. In a transmission line of a negligible resistance, the Surge impedance will be

Q22. Surge impedance loading (SIL) is represented by

Q23. The diameter of each strand is "d" then the diameter of n-layer stranded conductor will be:

Q24. In transmission line which conductors are used ?

Q25. The function of steel wire in ACSR conductors is

Q26. Which type of insulators are used on 132 kV transmission lines?

Q27. A 3-phase transmission line is being supported by three disc insulators. The potentials across top unit (i.e., near to the tower) and middle unit are 8 kV and 12 kV respectively. Calculate the string efficiency.

Q28. Wooden pole are used as line supports for voltage upto

Q29. A guard ring is used in string type insulator having \(4\) units to improve string efficiency. Find the capacitance of metal link \(3\) if pin to earth capacitance of each unit is \(1 \: F\).

Q30. A string insulator has \(3\) units. The voltage across bottom most unit is \(11 kV\) and its efficiency is \(85 \%\). Find the total operating voltage.