Impedance Z given as
![Z=\sqrt{(X_C^2-X_L^2)+R^2}](/tpl/images/0386/0090/34f48.png)
At resonance
![X_C=X_L](/tpl/images/0386/0090/a34f2.png)
![Z=\sqrt{(X_C^2-X_C^2)+R^2}](/tpl/images/0386/0090/8f73d.png)
Z=R
At the resonance condition the impedance of a series RLC will be equal to the R.
---------------------------------------------------------------------------------------------
The quality factor of the circuit depends on R ,L ,C and width of the resonance.
Quality factor Q
![Q=\dfrac{f}{BW}](/tpl/images/0386/0090/ed690.png)
BW= Band width
f=Frequency at resonance