In an LCR ac circuit, the resistance and reactances R,XC and XL are in the ratio 1 : 3 : 4 .The frequency of ac is f0. The resonant frequency of the circuit will be
34f0
43f0
f0
XLXC=ω2(LC)=43, f0=12π43LC,
now XL=XC⇒ω2=1LC⇒fr=12π1LC