Give the name of the physical quantity in an $LCR$ circuit that corresponds to the damping constant in forced oscillations.

$L$,$C$,and $R$ denote inductance,capacitance,and resistance respectively. Pick out the combination which does not have the dimensions of frequency.

In an electrical circuit,$R, L, C$ and an $a.c.$ voltage source are all connected in series. When $L$ is removed from the circuit,the phase difference between the voltage and the current in the circuit is $\pi /3$. If instead,$C$ is removed from the circuit,the phase difference is again $\pi /3$. The power factor of the circuit is

In an $LCR$ series circuit,when $L$ is removed from the circuit,the phase difference between voltage and current is $\frac{\pi}{3}$. If $C$ is removed from the circuit instead of $L$,the phase difference is again $\frac{\pi}{3}$. The power factor of the circuit is $(\tan 60^{\circ}=\sqrt{3})$.

$A$ coil has inductance of $0.4 \text{ H}$ and resistance of $8 \Omega$. It is connected to an $AC$ source with peak emf $4 \text{ V}$ and frequency $\frac{30}{\pi} \text{ Hz}$. The average power dissipated in the circuit is (in $\text{ W}$)

The effective current $I$ in the given circuit at very high frequencies will be $.......A$