Question 14.11: If the bandstop filter in Fig. 14.37 is to reject a 200-Hz s......

We use the formulas for a series resonant circuit in Section 14.5.

B =  2π (100) =  200π  rad/s

But

B = \frac{R}{L }      ⇒       L = \frac{R}{B} = \frac{150}{200π} = 0.2387  H

Rejection of the 200-Hz sinusoid means that  f_{0} is  200 Hz, so that ω_{0}   in Fig. 14.38 is

ω_{0} =  2π f_{0} = 2π (200) =  400  π

Since ω_{0}  = 1/ \sqrt{LC} ,

C = \frac{1}{ω^{2}_{0}L} = \frac{1}{(400π)^{2}(0.2387)} = 2.653  μF