Question

An LC circuit like that in the figure below consists of a 3.40-H inductor and an 850-pF capacitor that initially carries a 105-

Answer 1

An L C circuit consits of inductor L = 3.40 H

Cpacitance of a capacitor is C = 850*10^-12 F

Initial charge of the capacitance is Q = 105*10^-6 C

a ) Energy stored in a capacitor is E = 1/2 Q^2 /C

                                                           = ( 105*10^-6 C )^2 / 2 * 850*10^-12 F

                                                           = 6.48J

b)

Energy stored in an inductor is   E_L = 1/2 LI^2

        current in the inductor is I = dQ / dt

                                                 = ( 0 - 105*10^-6 C / 0-2.00*10^-3 s)

                                                 = 52.5 *10^-3 s

      E_L =   1/2 * 3.40( 52.5 *10^-3 s)^2

              = 0.0046 J

c ) Total energy is T.E = 6.48 J + 0.0046 J

                                      = 6.484 J

                                      = 6.48 J   (rounded)