All Problems

Electric Oscillations

Problem 4.133

A circuit consisting of a capacitor and a coil connected in series is fed two alternating voltages of equal amplitudes but different frequencies. The frequency of one voltage is equal to the natural oscillation frequency \(\left(\omega_{0}\right)\) of the circuit, the frequency of the other voltage is \(\eta\) times higher. Find the ratio of the current amplitudes \(\left(I_{0} / I\right)\) generated by the two voltages if the quality factor of the system is equal to \(Q .\) Calculate this ratio for \(Q=10\) and \(100,\) if \(\eta=1.10 .\)

Reveal Answer
I0/I=1+(Q2+1/4)(η21)2/η2,2.2 and 19 respectively. I_{0} / I=\sqrt{1+\left(Q^{2}+1 / 4\right)\left(\eta^{2}-1\right)^{2} / \eta^{2}}, 2.2 \text { and } 19 \text { respectively. }