A power system consists of $$300$$ buses out of which $$20$$ buses are generator buses, $$25$$ buses are the ones with reactive power support and $$15$$ buses are the ones with fixed shunt capacitors. All the other buses are load buses. It is proposed to perform a load flow analysis for the system using Newton-Raphson method. The size of the Newton-Raphson Jacobian matrix is

If the reference bus is changed in two load flow runs with same system data and power obtained for reference bus taken as specified P and Q in the latter run

In load-flow analysis, a voltage-controlled bus is treated as a load bus in subsequent iteration for a _________limit is violated.

In load flow analysis, the load connected at a bus is represented as