What is the primary function of a resistor?

The primary function of a resistor is to control the flow of electricity in a circuit. Resistors provide resistance to the flow of electric current, which means they can limit the amount of current that can pass through a circuit. This property is important in various applications, such as protecting sensitive components from receiving too much current, dividing voltages, and controlling signal levels. By adjusting the resistance value, you can effectively manage how much current flows and how voltage is distributed in the circuit, allowing for the proper functioning of electronic devices.

While resistors can also generate heat as a byproduct of this process due to electrical energy being converted into thermal energy, the primary role is not to generate heat itself but to regulate the flow of electricity. Reducing voltage across certain components is a secondary effect of how resistors interact with current flow, and resistors do not increase current as that would contradict Ohm's law, which states that current through a conductor is directly proportional to the voltage across it, given a constant resistance.