Aparallel plate capacitor of 100 pf having an air dielectric is charged to 10 kilovolts. It is then electrically isolated. The plates are pulled away from each other until the distance is ten times more than before. Estimate the energy neededto pull the plates.-

A

0.05 Joules

B

50 Joules

C

500 Joules

D

-50 Joules