Read the following passage and then answer questions on the basis of your under standing of the passage and the related studied concepts. Passage: For an LCR series circuit driven with an alternating voltage of amplitude Vmand angular frequency oo, the current amplitude is given as
`I_(m) =V_(m)/z = V_(m)/sqrt(R^(2) + (X_(L)-X_(C))^(2)) =V_(m)/sqrt(R^(2) + (Iomega -1/(c omega))^(2))`
If `omega` is varied then for a particular frequency `omega_(0), X_( C) = X_(L)` and then Z = R and hence, `I_(m) = V_(m)/R` is maximum. This frequency is called the resonant frequency. The resonant frequency `omega_(0) = 1/sqrt(LC)` = Resonance of a LCR series a.c. circuit is said to be sharping current amplitude Im falls rapidly on increasing/decreasing the angular frequency from its resonant value 0. Mathematically, sharpness of resonance is measured by the quality factor of the circuit, which is given as:
`Q = (omega L)/R = 1/R sqrt(L/C)`
(b) How does impedance of the circuit changes with `omega`

Explanation

Variation of impedance Z with `omega` is shown here.