A buck converter feeding a variable resistive load is shown in the figure. The switching frequency of the switch $$S$$ is $$100$$ $$kHz$$ and the duty ratio is $$0.6.$$ The output voltage $${V_0}$$ is $$36$$ $$V.$$ Assume that all the components are ideal, and that the output voltage is ripple-free. The value of $$R$$ (in $$Ohm$$) that will make the inductor current ($${{\rm I}_L}$$) just continuous is _______.

A self commutating switch $$SW,$$ operated at duty cycle $$\delta $$ is used to control the load voltage as shown in the figure

Under steady state operating conditions, the average voltage across the indicator and the capacitor respectively, are

The single-phase full-bridge voltage source inverter $$(VSI),$$ shown in figure, has an output frequency of $$50$$ $$Hz$$. It uses unipolar pulse width modulation with switching frequency of $$50$$ $$kHz$$ and modulation index of $$0.7.$$ For
$${V_{in}} = 100\,V\,\,DC,\,\,L = 9.55\,\,mH,\,C = 63.66\,\,\mu F,$$ and $$R = 5\,\Omega ,$$ the amplitude of

A 50 Hz generating unit has H-constant of 2 MJ/MVA. The machine is initially operating in steady state at synchronous speed, and producing 1 pu of real power. The initial value of the rotor angle $$\delta $$ is $${5^ \circ }$$, when a bolted three phase to ground short circuit fault occurs at the terminal of the generator. Assuming the input mechanical power to remain at 1 pu, the value of $$\delta $$ in degrees, 0.02 second after the fault is _____________