PhysicsCode 5054
Electromotive force and potential difference
What this topic asks you to be able to do
- Define e.m.f. (electromotive force) as the electrical work a source does to move a unit charge all the way round a complete circuit; recall e.m.f. = work done (by a source) / charge, E = W / Q, and use this equation
- Define p.d. (potential difference) as the work done by each unit of charge as it passes through a component; recall p.d. = work done (on a component) / charge, V = W / Q, and use this equation
- Know that the volt is the unit of both e.m.f. and p.d., and that one volt is one joule per coulomb (J/C)
- Outline how analogue and digital voltmeters, which cover different ranges, are employed
- Work out the overall e.m.f. when a number of sources are connected in series
- State that when identical sources are linked in parallel, their e.m.f. is the same as the e.m.f. of a single source