Problem 4.128

An oscillating circuit consists of a capacitor of capacitance \(C\) and a solenoid with inductance \(L_{1} .\) The solenoid is inductively connected with a short-circuited coil having an inductance \(L_{2}\) and a negligible active resistance. Their mutual inductance coefficient is equal to \(L_{12}\). Find the natural frequency of the given oscillating circuit.