Given here, f=2kHz=2000Hz,C=62.5nF=62.5×10−9FandR=50Ω
Resonance frequency (amplitude of the current will be maximum in this case) is given by f=2πLC1, here, L is the inductance.
Putting the values,
2000Hz=2πL×62.5×10−91
L=4π2×20002×62.5×10−91=0.1H=100mH