Question

To reduce the resonant frequency in an $LCR$ series circuit with a generator.

• A. The generator frequency should be reduced
• B. Another capacitor should be added in parallel to the first
• C. The iron core of the inductor should be removed
• D. Dielectric in the capacitor should be removed

Answer 1

The correct option is B Another capacitor should be added in parallel to the first

Resonant frequency in series LCR circuit is
$v_r=\frac{1}{2\pi \sqrt{LC}}$
If capacitance C increases the resonant frequency will reduce, which can be achieved by adding another capacitor in parallel to the first.