The given figure represents the phasor diagram of a series $\mathrm{LCR}$ circuit connected to an $\mathrm{ac}$ source. At the instant $t$' when the source voltage is given by $V=V_0 \cos \omega t$', the current in the circuit will be

If $I_1, I_2, I_3$ and $I_4$ are the respective r.m.s. values of the time varying currents as shown in the four cases $\mathrm{I}, \mathrm{II}, \mathrm{III}$ and $\mathrm{IV}$. Then identify the correct relations

In the circuit diagram shown, $X_C=100 \mathrm{\Omega }, {\mathrm{X}}_{\mathrm{L}}=200\mathrm{\Omega }$ and $R=100 \mathrm{\Omega }.$ The effective current through the source is

In the shown $\mathrm{AC}$ circuit phase different between currents $I_1$ and $I_2$ is