The frequency of oscillation of a Hartley Oscillator is given as :
1
\(\rm \omega_O=\frac{L_1+L_2}{L_1L_2C}\)
2
\(\rm \omega_O=\frac{1}{\sqrt{(L_1+L_2)}C}\)
3
\(\rm \omega_O=\sqrt{\frac{L_1+L_2}{L_1L_2C}}\)
4
\(\rm \omega_O=\frac{2\pi}{\sqrt{(L_1+L_2)}C}\)