The insulation level of a $$400$$ kV, EHV overhead transmission line is decided on the basis of

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 insulation resistance of a cable of length $$10$$ km is $$1$$ $$M\Omega $$. For a length of $$100$$ km of the same cable, the insulation resistance will be

In a $$400$$ kV network, $$360$$ kV is recorded at a $$400$$ kV bus. The reactive power absorbed by a shunt reactor rated for $$50$$ MVAR, $$400$$ kV connected at the bus is