Ampere’s Law

Ampere’s Law - Definition & Applications

Ampere’s circuital law is an integral part of studying electromagnetism. The law defines the relationship between the current and magnetic field that it creates around itself. This law was named after the scientist Andre Marie Ampere who discovered this phenomenon.

Ampere conducted multiple experiments to comprehend how the forces acted on wires which carry current. To understand what is ampere's law, students have to have a clear understanding of both the magnetic and electric field. 

What is Ampere’s law?

The ampere's law definition states that ‘the line integral of a magnetic field intensity along a closed path is equal to the current distribution passing through that loop’. 

This above statement might be quite difficult to apprehend at once. Hence it is advisable to build a background for the same while understanding it.

Mathematical Expression

Let us look at the mathematical expression of the ampere circuital law for clarification.

[Image will be Uploaded Soon]

Herein, B is magnetic field intensity, I is current passing through a loop, and μ is magnetic flux. The image beside shows passage of current (represented with an upward moving arrow).

It depicts that on continuous passage of current, a magnetic field is created around the conductor. As a student you should understand that when you try to explain ampere's circuital law in regard with the passage of a current , it indicates that a conductor  is carrying current. 

Other than this, you should also have prior understanding of magnetic flux. The most vital topic to understand this is Gauss’s law which is usually one of the first topics that is taught. Once you have cleared the concept of this law, understanding ampere's law will be much easier. 

Ampere’s Circuital Law and Magnetic Field: Applications

Ampere's law, because of its convenience, has gained momentum since its inception. It has been implemented in real-life scenarios too. One of the most widely known platforms where Ampere’s law is being implemented regularly is the manufacturing of machines.

These machines can be motors, generators, transformers or other similar devices. All of these work with the principles related to application of ampere circuital law. Hence, understanding these concepts is essential especially since these are essential in higher standards. These concepts are the basis of some of the most vital derivations and principles which are relevant in Physics. 

Here is a list of applications where you will find Ampere’s circuital law being put into use. 

  • Solenoid

  • Straight wire

  • Thick wire

  • Cylindrical conductor

  • Toroidal solenoid

It should be noted that the working principle of this law remains the same throughout every process, even though its implementation varies greatly. It is the working principle of numerous machinery and devices, which are often even implemented as parts of other devices. 

Students may also go through the Ampere circuital law derivation to build a deeper understanding of the same. Not only is this derivation integral to Ampere’s law, but also since it is one of the fundamental concepts of Physics and electricity.

Notably, a diagram always helps and our study materials provide just that along with a lucid language for an explanation. To know more about what is ampere circuital law and its features with various applications in real life, you can check our online study programs. Herein, you will get access to high quality study materials with a quick explanation by subject experts. 

You can even download our Vedantu app which is easily available, so that you can access all the study materials at any time.

FAQ (Frequently Asked Questions)

1. How do You State Ampere's Circuital Law?

Ans. Ampere’s circuital law is stated as the relationship between a current-carrying conductor and the magnetic field created around the conductor due to its flow of current.

2. State and Explain Ampere's Circuital Law With the Necessary Equation.

Ans: To define the define ampere circuital law, let us consider the mathematical equation for Ampere's law -

∮ B. dl = μ0. I 

Where, ∮ is the integral of a closed surface on an imaginary plane, B is the magnetic flux, dl is an infinitesimal length on the circumference of the area enclosed, and I is the current carried by the conductor. 

3. What is the Most Popular Application of Ampere’s Circuital Law?

Ans: Some of the most widely used practical application of ampere's circuital law is its usage in motors, generators, transformers, etc.