A battery does not store current, it stores a push: a fixed amount of energy handed to every unit of charge that passes through. Track that energy as it is given out and used up, and the ideas of e.m.f. and potential difference fall into place.
The electromotive force of a source is the electrical energy given to each unit of charge by the source. The potential difference across a component is the energy transferred from each unit of charge in it. Both are measured in volts by a voltmeter connected in parallel.
The electromotive force (e.m.f.) of a source is the energy given to each unit of charge by the source. The potential difference (p.d.) across a component is the energy transferred from each unit of charge in it.
A voltmeter is connected in parallel, across the component.
Connect a voltmeter across the source and across components to compare the energy per charge.
Four quick checks. Each correct answer earns XP and lights this skill on your star map.
A voltmeter is connected...
The unit of e.m.f. and potential difference is the...
One volt is equal to one...
The e.m.f. of a cell is the energy given to each...
The source gives energy to each charge as e.m.f.; components take energy from each charge as p.d.
A voltmeter is connected in parallel, across the component, not in series. The volt is a joule per coulomb, the energy carried by each unit of charge.
Unlocks once the four checks above are done. Worth more XP, written in the style of Paper 2.
To measure the potential difference across a lamp, a voltmeter is connected...
A charge of 2.0 C passes through a lamp and transfers 12 J of energy. The p.d. across the lamp is...
The difference between e.m.f. and p.d. is that e.m.f. is energy...
EMF and potential difference are mapped. Keep the chain going.