पावर सिस्टम में निम्नलिखित में से किसे सममित दोष (Symmetrical Fault) के रूप में वर्गीकृत किया गया है?

In load flow analysis using the Newton-Raphson method, the bus at which both real power (P) and reactive power (Q) are specified is called a:

For a given base voltage and base volt-ampere, the per-unit impedance value of an element is X. What will be the new per-unit impedance value of this element when both the voltage and volt-ampere bases are doubled?