## State Ampere’s Circuital Law

**Ampere’s** **circuital** **law** states that the line integral of the magnetic field around any closed path is equal to the permeability of free space times the current passing through the enclosed area:

∮ B · dl = μ0 I_enc

where ∮ B · dl is the line integral of the magnetic field B around the closed path, μ0 is the permeability of free space, and I_enc is the total current passing through the area enclosed by the closed path.

This law relates the magnetic field to the current that produces it and is a fundamental principle of electromagnetism. It is applicable to any closed path, whether it is a simple loop or a more complex shape.

**What is Ampere’s Circuital Law**

Ampere’s circuital law is one of the four Maxwell’s equations, which are a set of fundamental equations describing the behavior of electric and magnetic fields. It was first formulated by André-Marie Ampère in 1826 and was later incorporated into Maxwell’s equations.

The law can be used to calculate the magnetic field generated by a current-carrying wire or a solenoid, as well as to determine the current passing through a closed path by measuring the magnetic field along the path. It is also useful in the design of electromagnetic devices such as transformers and motors.

**Features of Ampere’s Circuital Law**

One important feature of Ampere’s circuital law is that it only applies to steady-state currents, where the current and magnetic field is constant over time. For time-varying currents, the law must be modified to include additional terms that account for the changing electric field.

In addition, Ampere’s circuital law is closely related to the concept of magnetic flux, which is the amount of magnetic field passing through a surface. By applying the law to a surface enclosing a current-carrying wire, one can derive an expression for the magnetic flux through the surface, which is proportional to the current passing through the wire.

Overall, **Ampere’s** **circuital** **law** is a fundamental principle of electromagnetism that is widely used in many areas of science and engineering.

### Ampere Circuital Law Class 12

Ampere’s circuital law is one of the four Maxwell’s equations that describe the relationship between electric currents and magnetic fields. It states that the line integral of the magnetic field around a closed loop is equal to the current passing through the loop multiplied by a constant called the permeability of free space (μ0).

In mathematical terms, Ampere’s circuital law can be expressed as:

∮ B ⋅ dl = μ0 I

where:

- ∮ denotes the line integral taken around a closed loop
- B is the magnetic field vector
- dl is an element of the closed loop
- I is the current passing through the loop
- μ0 is the permeability of free space, which has a value of approximately 4π x 10^-7 T m/A.

Ampere’s circuital law can be used to calculate the magnetic field around simple current-carrying geometries such as straight wires, solenoids, and toroids. It is also used in conjunction with other Maxwell’s equations to describe the behavior of electromagnetic waves and to develop the theory of electromagnetism.