Question

A resistor $R_1$, an inductor L and a capacitor C are connected in series to an oscillator of frequency $\nu$. If the resonant frequency is ${\nu }_r$ , then the current lags behind voltage, when ____.

Answer 1

The current will lag behind the voltage when reactance of inductor is more than the reactance of capacitor. Thus,

$\omega L>\frac{1}{\omega C}$

$\omega >\frac{1}{\sqrt{LC}}$

This can be written as $\nu =\frac{1}{2\pi \sqrt{LC}}$

$\nu >{\nu }_r$

Where ${\nu }_r=$ resonant frequency.