What is the purpose of a resistor in a circuit?

The purpose of a resistor in a circuit is to impede current flow. Resistors are fundamental components that control the amount of electrical current that passes through a circuit. This ability to reduce the flow of current is crucial for protecting sensitive components from excessive current, managing voltage levels, and allowing for the correct functioning of various circuit elements.

By dissipating energy in the form of heat, resistors help to regulate the circuit's overall behavior, ensuring that devices receive the appropriate amount of current they need to operate effectively. This characteristic is what makes them essential for creating specific conditions required in an electronic circuit, such as forming voltage dividers or setting current levels for transistors and other components.