What are resistors used for?

1 Answer
Aug 25, 2014

Resistors are used to reduce voltage or current in a circuit. Of course a resistor will do both since they are all related through #V=IR#.

Some parts of a circuit may require certain voltages to work. If your power source generates too much voltage, you can put a resistor in series to get the right voltage to the part.

Other parts of a circuit may require limiting current. For instance you have a capacitor that is fully charged and you want to discharge it but limit the current. Again, you would put a resistor in series to do this.

A resistor that provides an variable amount of resistance is called a potentiometer. These are commonly attached to knobs. For example a volume control on a stereo; the "pot" is connected to the base of a transistor to control the amount of amplification to a speaker. Another example is controlling the amount of power going to an electric motor.

There are other uses too, but these are the basic ones.