What does a resistor do in an electrical circuit?

In an electrical circuit, a resistor plays a crucial role by regulating the flow of current. Its primary function is to resist the flow of electric current, creating a voltage drop across its terminals according to Ohm's Law, which states that the voltage (V) across a resistor is equal to the current (I) flowing through it multiplied by its resistance (R), or V = IR. By doing this, the resistor controls how much current flows through the circuit, which is essential for protecting sensitive components from excessive current that could cause damage, as well as ensuring that everything functions within its designed operational range.

The ability to regulate current flow is particularly important in applications where specific voltage levels must be maintained to avoid issues such as overheating or failure of electronic components. Resistors are fundamental components in various electrical applications, including voltage dividers, current limiters, biasing circuits, and many other functions where controlling current is necessary.