In an LCR circuit, capacitance is charged from C to 4C. For resonant frequency to remain unchanged, the inductance should be changed from L to

L/2 L/4 4L None of the above

L/4

Since the resonant frequency did not change                                                     f1= f2                                                L1C1 = L2C2 = L2(4C1)                                                   L2 = L1/4