A capacitor in an LC oscillator has a maximum potential difference of 15 V and a maximum energy of 360 $\mu$J.At a certain instant the energy in the capacitor is 40 $\mu$J.At that instant what is the potential difference across the capacitor?
A)0 V
B)5 V
C)10 V
D)15 V
E)20 V

Question

Quizplus · Accepted Answer

The energy stored in a capacitor is given by E = 1/2 CV^2, where E is the energy in joules, C is the capacitance in farads, and V is the potential difference in volts. If the maximum energy is 360 $\mu$J and the maximum potential difference is 15 V, then the capacitance is:C = 2E/V^2 = 2(360 $\mu$J)/(15 V)^2 = 32 $\mu$FIf the energy at a certain instant is 40 $\mu$J, then the potential difference at that instant is:V = sqrt(2E/C) = sqrt(2(40 $\mu$J)/32 $\mu$F) = 5 VTherefore, the correct answer is B) 5 V.

A Capacitor in an LC Oscillator Has a Maximum Potential μ\muμ

A Capacitor in an LC Oscillator Has a Maximum Potential $\mu$