L-C Circuit (Series) connected with AC power
There are lots of tutorials on RLC 
Basically you are amplifying applied voltage into stored voltage or energy ( that cannot be used with out reducing the energy and Q)   

It is just like having pinging a tuning fork that oscillates forever without loss until you add resistance.

\$\omega=2\pi f=\dfrac{1}{\sqrt{LC}}\$  and

Q= voltage gain = impedance gain since they all share the same current in series.
Let me use Qs for series and Qp for parallel RLC

\$Qs=\dfrac{X_L}{R}=\dfrac{X_C}{R}\$ at resonance frequency f where Xc=XL 

For parallel;   it is just the inverse.
\$Qp=R/X\$ at resonance f

Now I leave it up to your research to know what is X(f) impedance is for L and C as well as the stored energy if it could be applied to some load. This is useful for some applications like RF tuners to get voltage gain by impedance ratios.

Can you find the intersection of 3 variables to get Q and f. So with these variables you can change it by sliding along the line to find the intercept and X/R is your Q.

If your meter reads in reads 120V in rms and you applied 12V rms then you measured a gain of 10.