एक पावर सिस्टम लोड-फ्लो अध्ययन में, प्रत्येक बस या नोड कितनी बुनियादी विद्युत मात्राओं (quantities) से जुड़ा होता 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?