I'm having a difficult time finding any information in regards to LC circuits. The total energy in an circuit is 5.0*10^-6 J. If C= 15 microfarads, what is the charge on the capacitor? the ans is 12 microC An circuit has an inductance of 15 mH and a capacitance of 10 µF. At one instant the charge on the capacitor is 25 µC. At that instant the current is changing at what rate? ans : 170 A/s Again, I am unable to find the formula/information to solve these equations. Can someone please tell me what I am missing. I know the inductance equations (RLC) , but I don't see any in our book that contain just LC. Thank you.