Potentiometers, Trimmers & Rheostats are passive variable resistive components used to adjust resistance within an electrical circuit. They provide a controllable resistive element that can be set manually or during calibration to achieve a desired electrical condition.

• Potentiometers are adjustable resistors designed to provide a variable resistance with a movable contact, commonly used as an adjustable voltage-divider element.
• Trimmers (Trimmer Potentiometers) are compact adjustable resistors intended for fine adjustment and calibration, typically set during manufacturing, testing, or maintenance.
• Rheostats are variable resistors primarily used to control resistance in series with a circuit path, functioning as a two-terminal adjustable resistive element.

These components are selected based on their adjustment method, mechanical form, and intended adjustment frequency, providing a simple and reliable means of tuning circuit behavior without active electronics.