Problem 4.126

An alternating voltage with frequency $\omega=314 \quad s^{-1}$ and amplitude $V_{m}=180 \mathrm{~V}$ is fed to a series circuit consisting of a capacitor and a coil with active resistance $R=40 \Omega$ and inductance $L=0.36 \mathrm{H}$ . At what value of the capacitor's capacitance will the voltage amplitude across the coil be maximum? What is this amplitude equal to? What is the corresponding voltage amplitude across the condenser?

\begin{aligned} &\text { 4.126. For } C=\frac{1}{\omega^{2} L}=28 \mu \mathrm{F} ; V_{L}=V_{m} \sqrt{1+(\omega L / R)^{2}}=0.54 \mathrm{kV}\\ &V_{C}=V_{m} \omega L / R=0.51 \mathrm{kV} \end{aligned}

Electric Oscillations