State and explain principle of potentiometer

General
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state and explain principle of potentiometer

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The principle of a potentiometer

A potentiometer, also known as a pot, is a three-terminal device that is used to measure and control electrical potential difference or voltage. It operates on the principle of a variable resistor.

The key principle of a potentiometer is that it divides a voltage into two parts - a fixed voltage and a variable voltage. The variable voltage is proportional to the position of the sliding contact on the resistive element.

Working principle of a potentiometer

A potentiometer consists of a resistive element, a sliding contact, and three terminals. The resistive element is made of a material with a high resistivity, such as carbon or wirewound material. The sliding contact is a movable point that is connected to a wiper or a lever.

When a voltage is applied across the two ends of the resistive element, a potential gradient is formed along the length of the element. The sliding contact can be moved along the resistive element, changing the effective length of the resistive path.

By changing the position of the sliding contact, the ratio between the resistances on either side of the contact can be varied, causing a change in the potential difference or voltage at the output terminal.

Applications of potentiometers

Potentiometers have various applications in electrical and electronics circuits. Some of the common applications include:

  1. Volume control: Potentiometers are commonly used in audio systems to control the volume level. By varying the resistance, the volume can be increased or decreased.

  2. Light dimmer: Potentiometers are used in lighting circuits to dim or brighten the intensity of the light. The resistance is adjusted to control the power supplied to the light source.

  3. Voltage divider: Potentiometers can be used as voltage dividers to obtain a desired voltage level. By adjusting the position of the sliding contact, the output voltage can be varied.

  4. Calibration: Potentiometers are used in calibration procedures to adjust and calibrate various instruments, such as voltmeters, ammeters, and oscilloscopes.

In conclusion, the principle of a potentiometer is based on dividing a voltage into two parts using a variable resistor. By changing the position of the sliding contact, the voltage output can be varied. Potentiometers find applications in various electrical and electronic circuits for measurement and control purposes.