Problem 4.100

An oscillating circuit consists of an inductance coil \(L\) and a capacitor with capacitance \(C .\) The resistance of the coil and the lead wires is negligible. The coil is placed in a permanent magnetic field so that the total flux passing through all the turns of the coil is equa] to \Phi. At the moment \(t=0\) the magnetic field was switched off. Assuming the switching off time to be negligible compared to the natural oscillation period of the circuit, find the circuit current as a function of time \(t\).