A cell carries a current of $2.0\text{ A}$ through a circuit for $30\text{ s}$. During this interval, the cell transfers $120\text{ J}$ of energy. What is the electromotive force (e.m.f.) of the cell?
- A$0.50\text{ V}$
- B$1.5\text{ V}$
- C$2.0\text{ V}$
- D$8.0\text{ V}$