Potentiometer Working - Definition, Types, Application, FAQs

Edited By Vishal kumar | Updated on Sep 24, 2024 05:46 PM IST

In this article, we are going to discuss about potentiometer by answering the questions such as what is potentiometer, what is the potentiometer definition,what is the principle of potentiometer, what is the potentiometer formula and potentiometer working, what are the potentiometer types, what are the potentiometer applications and uses of potentiometer with the help of suitable potentiometer diagram

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What is a potentiometer?
Principle behind potentiometer working:
Application of Potentiometer

Potentiometer Working - Definition, Types, Application, FAQs

What is a potentiometer?

A potentiometer is an instrument which is made up of three terminal resistors in which has sliding or rotating contact that forms a voltage divider and this voltage driver is also adjustable. The potentiometer is used as the rheostat (also known as variable resistor), when it has two terminals that contain one end and wiper. In short, these potentiometers are also called “pots”.

this shows the rotation in the potentiometer

Principle behind potentiometer working:

The potentiometer contains a long resistive wire L, an emf battery V. This voltage V is also called driver cell voltage. Consider a primary circuit which is connected to the emf cell. The other end of the circuit is connected to G, galvanometer. And this circuit is considered to be a secondary circuit.

The potentiometer working is based on the potential across the wire and the length of the wire which has uniform area cross section and constant current flow shares a proportionality relation. In short, the principle behind the potentiometer working can be explained as the potential across the wire is directly proportional to the length of the wire. This can be expressed as

V=IR

Where, I denotes the current flow, R denotes the total resistance of the circuit, V denotes to the voltage

$\\R=\frac{\rho L}{A}\\V=I\frac{\rho L }{A}$

Where ρ denotes the resistivity of the material, A is used to denote the area cross section,

When, ρ and area is constant, then I current also becomes constant for the rheostat.

$\frac{\rho L }{A}=KV=KLE=\frac{L\rho x}{A}=Kx$

Where, x refers to the length of the potentiometer wire, E refers to the low EMF of the cell, K is a constant.

When the potential difference between the ends is zero, the galvanometer G shows null detection. This denotes that the flow of current in the circuit is also zero. Here, the x is considered to be the length of the null point. Now, unknown EMF is found from the following formula, E=Lρx/A=Kx

As the EMF has two cells, consider L1 to be the length of the null point of EMF cell E1 and L2 to be the length of the null point of EMF cell E2.E1 / E2=L1 / L2

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Types of potentiometer:

Let us see the different types of the potentiometer and also discuss them in detail.

Slider potentiometer (also known as slide potentiometer):
This type of potentiometer is adjustable by sliding the wiper in the right or left direction.
Thumbwheel potentiometer(also known as thumb potentiometer):
This type of potentiometer is adjustable with the small thumbwheel.
Trimmer potentiometer (also known as trim potentiometer):
This type of potentiometer is adjustable by the fine tuning of some electric signals.

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Types of rotating potentiometers:

Concentric potentiometer
Single turn potentiometer
Servo potentiometer

Concentric potentiometer:

Two different potentiometers are adjustable individually by the concentric shafts.These types of the potentiometers are used as control volume in the radios of old cars.
Single turn potentiometer:

This type of potentiometer is adjustable upto 270 degree with the help of single rotation. These types of potentiometers are used in controlling the resolution in single rotation.

Servo potentiometer:

Servo potentiometer can be adjusted by servo motors automatically. These types of potentiometers are used in volume control of remote control audio equipment.

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Types of Linear potentiometer:

Multi turn slide Potentiometer
Slide Potentiometer
Dual slide Potentiometer

Multi turn slide Potentiometer:

In the construction of multi turn slide Potentiometer, a spindle is used.

Slide Potentiometer:

In the construction of the slide Potentiometer, high quality fader is used. This potentiometer is used to measure distance.

Dual slide potentiometer:

Dual slide Potentiometers are used to control single and dual sliders which are connected in parallel.

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Application of Potentiometer

Linear and rotary Potentiometer is used in controlling the audio equipment to adjust the volume of the audio signals.
The potentiometer in televisions are used to control the brightness of the picture, color, and so on.
The potentiometers are also used in the motion control in position feedback devices like servo motors.
The potentiometers used in transducers are used to design the displacement transducers.
The potentiometers are used as control volume in the radios of old cars.

From this article, we saw about potentiometer , principle of potentiometer, , potentiometer formula and potentiometer working, its potentiometer types, potentiometer applications and uses of potentiometer. Now let us discuss some of the frequently asked questions from class 11 and class 12.

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NCERT Physics Notes:

Frequently Asked Questions (FAQs)

1. What is the principle of potentiometer or on what principle does the potentiometer work?

The principle behind the potentiometer working can be explained as the potential across the wire is directly proportional to the length of the wire. This can be expressed as V=IR. In detail, The potentiometer working is based on the potential across the wire and the length of the wire which has uniform area cross section and constant current flow shares a proportionality relation.

2. Define potentiometer or what does a potentiometer mean?

3. How does a multi turn potentiometer work?

In the construction of multi turn slide Potentiometer, a spindle is used. A wheel is attached to the spring which changes the linear position into a variable one.

4. Write one application of potentiometer

Linear and rotary Potentiometer is used in controlling the audio equipment to adjust the volume of the audio signals.
The potentiometer in televisions are used to control the brightness of the picture, color, and so on.
The potentiometers are also used in the motion control in position feedback devices like servo motors.
The potentiometers used in transducers are used to design the displacement transducers.
The potentiometers are used as control volume in the radios of old cars.

5. What is the null detector definition?

When the potential difference between the ends is zero, the galvanometer G shows null detection. This denotes that the flow of current in the circuit is also zero. The instrument is used to detect the zero current condition of a circuit, where the voltage between the endpoints are the same.

6. What is known as a resistive potentiometer?

The potentiometer is constructed to be adjustable with a variable resistor made of 3 different terminals. Two terminals in that are connected such that they are connected to the opposing ends of the resistive element.

7. Name some of the types of potentiometer:

There are a lot of potentiometers in practice and each vary from their uses and applications. Some of the potentiometer is listed below: