A 9.0 V battery is connected to a 2.50 μF capacitor. How much energy is stored in the capacitor?

Answer 1

You can use the potential energy equation. Be careful with units!

E = 1/2 C V²

E = 0.5 (2.5×10^-6 F) (9 V)² = 101×10^-6 J = 101 μJ

Note you can also use the capacitance equation Q = CV to change the variables in the energy equation.