When 4 volts e.m.f. is applied across a 1 farad capacitor, it will store energy of

Q. When 4 volts e.m.f. is applied across a 1 farad capacitor, it will store energy of

1. 2 joules
2. 4 joules
3. 6 joules
4. 8 joules

Answer: 8 joules