a 10 uF capacitpr is connected to a 12 V battery till its fully charged. it is then disconnected and to an uncharged 20 uF capacitor. find energy stored on 20 uF capaciotr when it has reached an electro static equilibrium

The charge on 10μF capacitor = 10 x 12 x 10⁻⁶ = 120 μC

when it is connected with 20μF capacitor both acquires common potential whose value is

= 120 x 10⁻⁶ / (10 + 20) x 10⁻⁶ = 4 V.

Energy stored in 20μF capacitor = 1/2 x 20 x 10⁻⁶ x 4 x 4 = 160 x 10⁻⁶ J.