Question

Suppose the initial charge on the capacitor in Exercise 7.7 is 6 mC.What is the total energy stored in the circuit initially? What is the total energy at later time?

Answer 1

Given: The values of initial charge on the capacitor is 6 mC, the capacitance of the capacitor is 30 μF and inductance of the inductor is 27 mH.

The total energy stored initially in the circuit is given as,

E i = 1 2 Q 2 C

Where, capacitance of the circuit is Cand charge stored in the capacitor is Q.

By substituting the values in the above equation, we get

E i = 1 2 ( 6× 10 −3 ) 2 30× 10 −6 =0.6 J

Thus, energy stored initially in the given circuit is 0.6 J.

The energy stored in the circuit will remain constant. Thus, the energy stored at a later time is also 0.6 J.