The impedance value of a generator is 0.2 pu on a base value of 11 KV, 50 MVA. The impedance value for a base value of 22 KV, 150 MVA is

Four identical alternators each rated for 20 MVA, 11 kV having a sub transient reactance of 16% are working in parallel. The short- circuit level at the bus-bars is

In a power system with negligible resistance, the fault current at a point is 8.00 pu. The series reactance to be included at the fault point to limit the short-circuit current to 5.00 pu is

The bus-bars of each of the two alternators of 15% reactance each, are interconnected through tie-bar reactors of 15% each. The equivalent impedance to fault current for a 3-phase fault in any alternator bus-bar will be

When a 50 MVA, 11 kV, 3-phase generator is subjected to a 3-phase fault, the fault current is –j5 pu. When it is subjected to a line-to-line fault, the positive sequence current is j4 pu. The positive and negative sequence reactances are respectively

The per unit impedance of a synchronous machine is 0.242. If the base voltage is increased by 1.1 times, the per unit value will be

A transmission line has 0.2 pu impedance on a base of 132 kV, 100 MVA. On a base of 220 kV, 50 MVA, it will have a pu impedance of

Four alternators, each rated at 5 MVA, 11 kV with 20% reactance are working in parallel. The short-circuit level at bus bars is

An isolated synchronous generator with transient reactance equal to 0.1 pu on a 100 MVA base is connected to the high voltage bus through a step up transformer of reactance 0.1 pu on 100 MVA base. The fault level at the bus is

The load currents in short circuit calculation are neglected because
1. Short circuit currents are much larger than load currents
2. Short circuit currents are greatly out of phase with load currents
Which of these statement(s) is/are correct ?