Correct Answer - Option 1 : resonance frequency to bandwidth
The quality factor Q is defined as the ratio of the resonant frequency to the bandwidth.
\(Q=\frac{{{f}_{r}}}{BW}\)
fr = resonant frequency
For a series RLC circuit, the resonance frequency is calculated as:
\(f_r=\frac{1}{\sqrt{LC}}\)
Also, the bandwidth of a series RLC circuit is calculated as:
\(BW=\frac{R}{L}\)
Substituting this in Equation (1), we get:
\(Q=\frac{{{f}_{r}}}{BW}=\frac{1}{R}\sqrt{\frac{L}{C}}\)