A resistor is a passive electronic component that restricts the flow of electric current in a circuit, creating a voltage drop across its terminals. It is characterized by its resistance value, measured in ohms (Ω), which determines how much it opposes the current. Resistors are used to control current levels, divide voltages, and dissipate power as heat. They come in various types and sizes, and are essential in virtually all electronic circuits for setting operating conditions and protecting components from excessive current.
 IEEE Resistor |
 IEC Resistor |