Q.

A 600 pF capacitor is charged by a 200 V supply. It is then disconnected from the supply and is connected to another uncharged 600 pF capacitor. Electrostatic energy lost in the process is __________μJ           [2023]


Ans.

(6)

Q=CV=600×10-12×200=12×10-8 C

Initial energy=12CV2

                          =12×600×10-12×(200)2=12μJ

When connected to another uncharged capacitor

charge will be equally distributed on identical capacitors

          Q'=Q2=6×10-8

Final energy=2×Q'22C=Q'2C

       =(6×10-8)2600×10-12=6μJ

Energy lost=Initial energy-Final energy

                       =(12-6)μJ=6μJ