For the configuration shown in figure, the breaker connecting a large system to bus $$2$$ is initially open. The system $$3$$-phase fault level at bus $$3$$ under this condition is not known. After closing the system breaker, the $$3$$-phase fault level at bus $$1$$ was found to be $$5.0$$ p.u. What will be the new $$3$$-phase fault level at system bus $$3,$$ after the interconnection? All per unit values are on common base. Prefault load currents are neglected and prefault voltages are assumed to be $$1.0$$ p.u. at all buses.

In a 3-step distance protection, the reach of the three zones of the relay at the beginning of the first line typically extends upto

In an inverse definite minimum time, electromagnetic type over-current relay, the minimum time feature is achieved because of

The plug setting of a negative sequence relay is $$0.2$$ $$A.$$ The current transformer ratio is $$5:1$$. The minimum value of line to line fault current for the operation of the relay is