Consider an air-filled parallel plate capacitor with plate area A and gap width d and plate charge Q. What is the total energy stored in the capacitor?
1 U = Q² d / 2 ε₀A
2. U = Q² A/ε₀d
3. U= QA / ε₀ d
4. U = Q² / ε₀ A d
5. U = Q / ε₀ A d
6. U = Q d / ε₀ A
7. U = Q / 2 ε₀Ad
8. U = Q² / 2 ε₀ A d