With respect to energy transfer $W$ and charge $q$, what is meant by potential difference (p.d.) and electromotive force (e.m.f.)?
- Ap.d.: $\frac{W}{q}$; e.m.f.: $\frac{W}{q}$
- Bp.d.: $\frac{W}{q}$; e.m.f.: $Wq$
- Cp.d.: $Wq$; e.m.f.: $\frac{W}{q}$
- Dp.d.: $Wq$; e.m.f.: $Wq$