A $50$ Hz $,4-$pole turbo generator rated $20$MVA,$13\mathrm{.}2kV$ has an inertia constant of $H=9\mathrm{.}0kW\frac{s}{k}VA.$ Determine the kinetic energy stored in the rotor at synchronous speed. Determine the acceleration if the input less the rotational loss is $25,000hp$ and the electric power developed is $15,000kW.$ If the acceleration computed for the generator is constant for a period of $15$ cycles, determine the change in torque angle in that period and the speed in revolutions per minute at the end of $15$ cycles. Assume that the generator is synchronized with a large system and has no accelerating torque before the $15-$cycle period begins.

Using the nominal$-$T method, find the A$,$ B$,$ C$,$ and D parameters of a $3-$phase $80km,50Hz$ transmission line with series reactance of $0\mathrm{.}15+j0\mathrm{.}78$ ohm per km and a shunt admittance of j $5$ x ${10}^{-6}$ mho per km$.$

A $2-$pole, $50Hz,11kV,$ turbo generator has a rating of $60$ MW $,$ a power factor of $0\mathrm{.}85$ lagging. Its rotor has a moment of inertia of $8,800kg-m^2.$ Calculate its inertia constant in MJ per MVA and its momentum in MJ$-$s$/$electrical degree.

A $400$ V $,3-$phase $4-$wire service mains supplies a star$-$connected load. The resistance of each line is $0\mathrm{.}1$ ohm and that of neutral is $0\mathrm{.}2$ ohm $.$ The load impedances are $Z_R=(6+j9),Z_Y=8$ ohms and $Z_B=(6-j8).$ Calculate the voltage across each load impedance and current in the neutral. Phase sequence RYB$.$

Determine the efficiency and regulation of a $3-$phase, $100km,50Hz$ transmission line delivering $20$ MW at a p$.$f$.$ of $0\mathrm{.}8$ lagging and $66$ kV to a balanced load. The conductors are of copper, each having a resistance of $0\mathrm{.}1$ ohms per $km,1\mathrm{.}5cm$ outside diameter, spaced equilaterally $2$ metres between centres. Neglect leakance and use $($i$)$ nominal$-$T$,$ and $($ii$)$ nominal $$ method.