Chapter 21 - AC Circuits - Learning Path Questions and Exercises - Exercises - Page 749: 23

a) $250Hz$ b) $990Hz$

a) $L=250mH$, $X_{L}=400Ohm$ Inductive reactance = $X_{L}=2\times pi\times f\times L$ Thus, $f=\frac{400}{2\times3.14\times250\times10^{-3}}=250Hz$ b) Capacitive reactance = $\frac{1}{2\times 3.14\times f\times C}=\frac{1}{2\times 3.14\times 0.4\times10^{-6}\times400}=990Hz$