Three phase to ground fault takes place at locations $${F_1}$$ and $${F_2}$$ in the system shown in the figure.

If the fault takes place at location $${F_1}$$, then the voltage and the current at bus A are $${V_F1}$$ and $${{\rm I}_{F1}}$$ respectively. If the fault takes place at location $${F_2}$$, then the voltage and the current at bus A are $${V_{F2}}$$ and $${{\rm I}_{F2}}$$ respectively.

The correct statement about voltages and currents during faults at $${F_1}$$ and $${F_2}$$ is

The undesirable property of an electrical insulating material is

A distribution feeder of $$1$$ $$km$$ length having resistance, but negligible reactance, is fed from both the ends by $$400$$ $$V,$$ $$50$$ $$Hz$$ balanced sources. Both voltage sources $${S_1}$$ and $${S_2}$$ are in phase. The feeder supplies concentrated loads of unity power factor as shown in the figure.

The contributions of $${S_1}$$ and $${S_2}$$ in $$100$$ $$A$$ current supplied at location $$P$$ respectively, are

The function shown in the figure can be represented as