The power factor of an AC circuit containing peak current 2 A and peak voltage 1 V is $1 / 2$, then the angle between voltage and current is

A generator produces a current of 100 A at 4000 V . The voltage is stepped up to $2 \times 10^5 \mathrm{~V}$ by a transformer before being sent on a high voltage transmission line of resistance $50 \Omega$. The percentage of power loss in the transmission line is

A capacitor of capacitance $100 \mu \mathrm{~F}$ and a coil of resistance $20 \Omega$ and inductance 12.5 mH are connected in series with a $220 \mathrm{~V}, \frac{200}{\pi} \mathrm{~Hz}, \mathrm{AC}$ source. The maximum value of instantaneous current in the circuit is

The $Q$ value of a series $L-C-R$ circuit with $L=2 \mathrm{H}$, $C=32 \mu \mathrm{~F}, R=20 \Omega$ is