Quality Factor is defined as the ratio of Resonance frequency per unit band width
it is given as
[tex]Q = \frac{\omega_0}{\Delta \omega}[/tex]
[tex]Q = \frac{2\pi f_0}{2\pi f_{fw}}[/tex]
now here it is given that
[tex]f_0 = 1.40 hz[/tex]
[tex]f_{fw} = 0.021 hz[/tex]
now we have
[tex]Q = \frac{2\pi*1.40}{2\pi*0.021}[/tex]
so we have
[tex]Q = 66.67[/tex]
So quality factor of given AC is 66.67
