# A 200 pF capacitor is included in the oscillating circuit. What inductance must be included in the circuit in order

**A 200 pF capacitor is included in the oscillating circuit. What inductance must be included in the circuit in order to receive electromagnetic oscillations with a frequency of 400 kHz in it?**

To calculate the required inductance of the circuit to obtain electromagnetic oscillations with the specified frequency, we use the formula: ν = 1 / (2Π * √ (C * L)); C * L = 1 / (4Π ^ 2 * ν ^ 2) and L = 1 / (C * 4Π ^ 2 * ν ^ 2).

Variables: C – capacitance of the switched on capacitor (C = 200 pF = 2 * 10 ^ -10 F); ν is the specified vibration frequency (ν = 400 kHz = 4 * 10 ^ 5 Hz).

Let’s make a calculation: L = 1 / (C * 4Π ^ 2 * ν ^ 2) = 1 / (2 * 10 ^ -10 * 4 * 3.14 ^ 2 * (4 * 10 ^ 5) ^ 2) = 7, 92 * 10 ^ -4 G.

Answer: It is required to turn on an inductance equal to 7.92 * 10 ^ -4 H to the circuit.