What is the primary function of a resistor in an electrical circuit?

The primary function of a resistor in an electrical circuit is to limit the flow of electricity. Resistors are passive components that provide resistance to the current, which is essential for controlling the amount of electrical energy that can pass through a circuit. By doing so, they help to protect sensitive components from receiving too much current, which can lead to damage or failure.

When current flows through a resistor, it encounters resistance, which causes a voltage drop across the resistor. This means that the overall current in the circuit is reduced according to Ohm's Law, where the voltage (V) across a resistor is equal to the product of the current (I) flowing through it and the resistance (R) of the resistor (V = I × R). This ability to regulate current makes resistors crucial in circuits for various applications, including voltage dividers, current limiters, and for biasing active components such as transistors.