Resistors are used to limit voltage and/or current in a circuit and can have a fixed or variable resistance. Variable resistors (often called potentiometers or rheostats) are used when dynamic control over the voltage/current in a circuit is needed, for example, in a light dimmer or volume control.
In an electrical circuit, resistors have fixed or __________ resistance.
series |
|
dynamic |
|
parallel |
|
variable |