In an outdoor substation the three bus-bar conductors are supported by units of post type insulators. Each unit consists of a stack of 3 pin type insulators fixed one on the top of the other. The...

Extracted text: In an outdoor substation the three bus-bar conductors are supported by units of post type insulators. Each unit consists of a stack of 3 pin type insulators fixed one on the top of the other. The voltage across the lowest insulator is 15kV and that across the next unit is 12kV. Estimate: ratio of mutual to self-capacitance i. the bus-bar voltage of the substation. Efficiency across the string of insulators ii. iii.