A resistor is a circuit component, with a specified electrical resistance, which is designed to reduce current. A resistor produces a voltage drop between its terminals in accordance with Ohm's law.


Resistors for electronic circuits are generally made from finely ground particles of carbon mixed with a ceramic material and enclosed in an insulated tube. The value of the resistance is given by a coded set of colored rings on the outside of the tube. resistors for carrying larger currents consist of coils of insulated wire.