E = 0.5 x 500 x 10-12 (F) x 10002 (V) = 2.5 x 10-4(J)2.5 x 10-4 x 1000 = 0.25 mJ註解:電容一般以毫法拉(mF,1mF = 10-3F)、微法拉(µF,1µF = 10-6F)、奈法拉(nF,1nF = 10-9F)或者皮法拉(pF,1pF = 10-12F)表示。J(焦耳),mJ(毫焦耳),MJ(兆焦耳)