Question

What do you mean by resonance in $LCR$ series circuit? Write the formula for resonant frequency.

Answer 1

The resonance of a series RLC circuit occurs when the inductive and capacitive reactances are equal in magnitude but cancel each other because they are 180 degrees apart in phase.

The sharp minimum in impedance which occurs is useful in tuning applications.

Now, the formula of resonant frequency is

$f_r=\sqrt{\frac{1}{4{\pi }^{2}LC}}$