The figure shows the circuit diagram of a rectifier. The load consists of a resistance $$10\,\Omega $$ and an inductance $$0.05$$ $$H$$ connected in series. Assuming ideal thyristor and ideal diode, the thyristor firing angle (in degree) needed to obtain an average load voltage of $$70$$ $$V$$ is _______________.

A diode circuit feeds an ideal inductor as shown in the figure. Given $${V_s} = 100\,\,\sin \,\left( {\omega t} \right)V,$$ where $$\omega = 100\pi $$ rad/s, and $$L=31.83$$ $$mH$$. The initial value of inductor current is zero. Switch $$S$$ is closed at $$t=2.5$$ $$ms.$$ The peak value of inductor current $${i_L}\left( {in\,\,A} \right)$$ in the first cycle is __________.

A three-phase fully controlled bridge converter is fed through star-delta transformer as shown in the figure.

The converter is operated at a firing angle of $${30^0}.$$ Assuming the load current $$\left( {{{\rm I}_0}} \right)$$ to be virtually constant at $$1$$ $$p.u.$$ and transformer to be an ideal one, the input phase current waveform is

The input voltage given to a converter is
$${V_i} = 100\sqrt 2 \,\,\,\sin \,\,\,\left( {100\pi t} \right)\,\,V$$
The current drawn by the converter is
$${i_i} = 10\sqrt 2 \,\,\,\sin \,\,\,\left( {100\pi t - {\pi \over 3}} \right)\,\, + 5\sqrt 2 $$
$$\sin \left( {300\pi t + {\pi \over 4}} \right)\,\, + \,\,2\sqrt 2 \,\,\sin \left( {500\pi t - {\pi \over 6}} \right)A$$

The input power factor of the converter is