Potential difference and EMF
difference (PD), potential dividers and potentiometers are ideas which you must
grasp for A level (16 to 19 year) physics.
Potential dividers are a combination of resistors in series that divide up the potential difference.
Potentiometers are used to provide a range of voltages for a supply that it is
useful to turn up and down - such as a volume control on a hifi and they are
used as transducers or detectors of movement. The basis
of the potentiometer is a potential divider.
EMF and internal resistance are hard to imagine and hard to measure however they
are important concepts which apply to all electricity generation - a dry cell,
a generator or a transformer.
To download a pdf copy of any of the pages of notes, click on the small
image below the slide show.
Potential difference, potential dividers, EMF and internal resistance