For the circuit shown in the figure to the right C1 300 mu

For the circuit shown in the figure to the right C_1 = 3.00 mu F, C_2 = 1.00 mu F, C_3 = 6.00 mu F. C_4 = 3.00 mu F, and C_5 = 3.00 mu F. If the potential difference across capacitor C_4 is 2.00 Volts, what is the energy stored in capacitor C_1?

Solution

PD across C4, V4 = 2 volts

charge on C4, Q4 = C4 V4 = 3 x 2 = 6uC

C3 and C4 are in series,

so Q3 = Q4 = 6 uC

V3 = Q3/C3 = 6uC / 6uF = 1 Volt

PD across C2 , V2 = 2 + 1 = 3 volt.

charge on C2, Q2 = 3 x 1uF = 3 uC

charge on C1, Q1 = (3uC) + (6uC) = 9 uC

Energy stored, U = Q^2 / 2C = (9 x 10^-6)^2 / (2 x 3 x 10^-6) = 1.35 x 10^-5 J .....Ans