The surge impedance of a $$400$$ km long overhead transmission line is $$400$$ $$\Omega $$. For a $$200$$ km length of the same line, the surge impedance will be

The rated load of an underground cable is always _______its natural load.

In order to have a lower cost of electrical energy generation,

The positive sequence component of the voltage at the point of fault in a power system is zero for a _________fault.