Define fixed resistor and variable resistor?

A fixed resistor is a type of resistor that has a fixed resistance value that cannot be changed. It is designed to have a specific resistance value and is used to limit the flow of electric current in a circuit.

A variable resistor, on the other hand, is a type of resistor that has a resistance value that can be adjusted manually. It allows the user to change the resistance value by turning a knob or sliding a lever, which in turn changes the flow of electric current in a circuit. Variable resistors are commonly used in applications where the resistance needs to be adjusted frequently, such as volume controls in audio equipment.