P.d. Across A Component

Potential difference (p.d.) between two points is the energy transferred per unit charge passing between those points. V = WQ where: `V` = potential difference in volts; `W` = energy transferred in joules; `Q` = charge in coulombs. Therefore: 1 V = 1 J/C

When charge passes through a resistor, lamp, motor, or other component, electrical energy is transferred into other forms. Examples: resistor → thermal energy; lamp → light + thermal energy; motor → mechanical + thermal energy. The p.d. across the component tells us how much energy is transferred **per coulomb of charge**.

A component transfers 60 J when 12 C passes through it. **V = WQ** 0 **V = 5 V**