In a $$L$$-$$R$$ circuit the inductive reactance is equal to the resistance $R$ in the circuit. An emf $$E=E_0 \cos \omega t$$ is applied to the circuit. The power consumed in the circuit is

In an oscillating LC circuit, the maximum charge on the capacitor is '$$Q$$'. When the energy is stored equally between the electric and magnetic fields, the charge on the capacitor becomes

With increase in frequency of a.c. supply, the impedance of an L-C-R series circuit

In an a.c. circuit the instantaneous current and emf are represented as $$\mathrm{I}=\mathrm{I}_0, \sin [\omega \mathrm{t}-\pi / 6]$$ and $$\mathrm{E}=\mathrm{E}_0 \sin [\omega \mathrm{t}+\pi / 3]$$ respectively. The voltage leads the current by