Now electrical circuits in which currents oscillate have a natural frequency of their own.
On emerging from the beam, however, these vibrations immediately resume their natural frequency.
Let us also make the condenser a variable one so that we can change the natural frequency or tune of the circuit.
One set of blades operates at its natural frequency as a tuning-fork oscillator.
This is the setting of the condenser for which the circuit has the same tune or natural frequency as the circuit cd.