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

Options

A. the galvanometer 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

B

Explanation

We know that resonant frequency in an L-C-R circut is given by
`v_(0) = 1/(2pisqrt(LC))`
Now to reduce `v_(0)` either we can increase L or we can increase C. To increase capacitance, we must connect another capacitor parallel to the first.