- a device for measuring electromotive force or potential difference by comparison with a known voltage.
- voltage divider.
- an instrument for determining a potential difference or electromotive force by measuring the fraction of it that balances a standard electromotive force
- a device with three terminals, two of which are connected to a resistance wire and the third to a brush moving along the wire, so that a variable potential can be tapped off: used in electronic circuits, esp as a volume control