Editing Voltage (section)

==Measuring instruments==

[[File:9VBatteryWithMeter.jpg|thumb|[[Multimeter]] set to measure voltage]]
Instruments for measuring voltages include the [[voltmeter]], the [[Potentiometer (measuring instrument)|potentiometer]], and the [[oscilloscope]]. [[Voltmeter|Analog voltmeter]]s, such as moving-coil instruments, work by measuring the current through a fixed resistor, which, according to [[Ohm's law]], is proportional to the voltage across the resistor. The potentiometer works by balancing the unknown voltage against a known voltage in a [[bridge circuit]]. The cathode-ray oscilloscope works by amplifying the voltage and using it to deflect an [[electron]] beam from a straight path, so that the deflection of the beam is proportional to the voltage.