In an electrical circuit containing a power supply and a load resistor, energy is continuously converted between different forms. Which of the following statements correctly defines the electromotive force (e.m.f.) of the supply and the potential difference (p.d.) across the load resistor in terms of energy transfer and charge?
e.m.f. is the energy transferred from non-electrical to electrical forms per unit charge, whereas p.d. is the energy transferred from electrical to other forms per unit charge.
e.m.f. is the energy transferred from electrical to non-electrical forms per unit charge, whereas p.d. is the energy transferred from non-electrical to electrical forms per unit charge.
e.m.f. is the energy transferred from non-electrical to electrical forms per unit current, whereas p.d. is the energy transferred from electrical to other forms per unit current.
e.m.f. is the energy transferred from electrical to non-electrical forms per unit current, whereas p.d. is the energy transferred from non-electrical to electrical forms per unit current.