P.d. Across a Component

P.d. Across a Component

Voltage across a component tells us how much energy each coulomb of charge transfers there.

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;

0 = charge in coulombs.

Therefore:

**1 V = 1 J/C**

Across a Component

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.

Worked Example

A component transfers 60 J when 12 C passes through it.

**V = WQ**

`=6012`

**V = 5 V**

P.d. Across a Component — Advanced

Potential difference is a difference in electric potential between two points. It connects circuit energy transfer with charge transport and provides the energy-per-unit-charge description of a component.