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

Options

A. the generator frequency should be reduced
B. another capactior should be added in paralle to the first
C. the iron core of the inductor should be removed
D. dielectric in the capacitor should be removed

Answer

B

Explanation

Resonant frequency in an LCR series circuit is `v_(r) = (1)/(2 pi sqrt(LC))`
To reduce `v_(r)` , c can be increased, by adding another capacitor in parallel to the first. Choice (b) is correct.