Need help with LC Circuit calculate the time

Thread Starter

Tessa R

Joined Jun 22, 2019
The question asks: In the circuit, the capacitor is fully charged when switch S is closed. Calculate the time needed for the potential energy stored by the circuit to be equally distributed between the capacitor and inductor. The capacitance is C=20.0MF and the inductance is L=65.0 H.

My attempt at this problem was to use the equation. 1/(LC)^sqroot and then taken that value solve for time using w=2pif
However since it is asking for potential energy do I have to use Qcos(wt)? I am just confused at how I could use the other potential energy equations I know without having the charge.

Would anyone be able to point me in the right direction of equations to use/how to set up the problem?

Thank you


Joined Mar 31, 2012
In what circuit?

Do you really mean 20 million farads?

Assuming that the two components are simply connected together in a lossless tank circuit once the switch is closed, what's the equation for the current and the voltage as a function of time? You know it is a sinusoid and you know the frequency and you know the initial conditions.