Where Does the Extra Energy in a Capacitor Come From?

[Ajay.makhecha]

A capacitor is connected to a battery. If a person pulls the plate to increase the distance by 2d the decrease in energy between the plates is E. We observe energy gained by battery is 2E. From where does extra energy E come from.?

 

[Dale]

From where does extra energy E come from.?

Where do you think it came from. Can you think of any quantity that is equal to the change in energy?

 

[Ajay.makhecha]

i think extra E came because of work done by external force

 

[Dale]

Yes, exactly!