The Q value affects the frequency selectivity of the circuit. When the circuit is at the resonant frequency, there is a maximum current, and the total current is small when it deviates from the resonant frequency. We use I/I0 to denote the ratio of the current through the circuit to the current in the resonant circuit, the relative rate of change. ω/ω0 indicates how far the frequency deviates from the resonant frequency. Figure 6 shows I/I0 versus ω/ω0. There are three curves here, corresponding to three different Q values, where Q1>Q2>Q3. It can be seen that when the applied signal frequency ω deviates from the resonant frequency ω0 of the circuit, I/I0 is less than 1.