In a series $LCR$ circuit,what will be the nature of the circuit for frequencies higher than the resonant frequency?

$A$ series resonant circuit consists of an inductor $L$ and capacitor $C$ which produces resonant frequency $f$. If $L$ is increased by $2L$ (making the new inductance $L' = L + 2L = 3L$) and $C$ is changed to $9C$, the new resonant frequency will be:

$A$ resistor of $100 \text{ } \Omega$, an inductor of self-inductance $(4/\pi^2) \text{ H}$, and a capacitor of unknown capacity are connected in series to an a.c. source of $200 \text{ V}$ and $50 \text{ Hz}$. When the current and voltage are in phase, the value of the capacity is: (in $\text{ } \mu\text{F}$)

In a series $LCR$ circuit,the frequency of the source is half of the resonance frequency. The nature of the circuit will be:

$A$ capacitor of $250\,\mu F$ is connected in parallel to a coil of inductance $0.16\,mH$, while its effective resistance is $20\,\Omega$. Determine the resonant frequency.

$A$ series $LCR$ circuit is connected to an ac voltage source. When $L$ is removed from the circuit,the phase difference between current and voltage is $\frac{\pi}{3}$. If instead $C$ is removed from the circuit,the phase difference is again $\frac{\pi}{3}$ between current and voltage. The power factor of the circuit is: