Question

Suppose that we have a 1000 pF parallel-plate capacitor with air dielectric charged to 1000 V. The capacitors terminals are open circuited. Find the stored energy. If the plates are moved apart so that d is doubled, determine the new voltage on the capacitor and the new stored energy. Where did the extra energy come from?

Answer 1

Answer:

A) initial stored energy = 5x10^-4 J

B) new voltage if space is doubled will be 2000V

C) if space is doubled, stored energy becomes 2x10^-3 J

D) the extra energy comes from the work done in moving the plates further apart

Explanation:

Detailed explanation and calculation is shown in the image below