The Ampere’s Law states that for a closed loop path, the sum of the length elements, times the magnetic field in the direction of the length element is equal to the permeability times the electric current enclosed in the loop.
This can be explained by a simple equation as-
The magnetic field in the space around an electric current is proven to be proportional to the electric current (serving as the source). Likewise, the electric field in space is proportional to the charge (serving at the source).
In case of electric field, the relation of the field to the source is quantified in the Gauss’s Law which helps in calculating the electric field.
VALIDITY FOR CONDUCTOR
The Ampere’s law is valid for all the closed paths that surround a conductor but is not always convenient to use. Many paths along which the integral is difficult to calculate, the Ampere’s Law isn’t used.
Ampere is the unit for measuring the electric current. Current is the amount or number of electrons flowing through a circuit. Amp is used to symbolise ampere. One amp is the amount of current which is produces by a force of one volt, which acts through the resistance of one ohm. Or, one amp can also be defined as the current flowing with electric charge of one Coulomb per second, where Coulomb is the amount of electricity carried in one second by the current of one ampere.
The unit is named after the French scientist, Andre-Marie Ampere in 1826.
APPLICATIONS OF THE AMPERE’S LAW
- The application of Ampere’s Law is possible only when all the currents are steady.
- Only the currents that cross the area inside the path can be taken into account and have some contribution to the magnetic field.
- Use right hand rule to determine the directions and signs for the currents. Currents need to be taken along with their algebraic signs (positive if going out of the surface and negative when going inside the circuit).
- The magnetic circulation is zero if the enclosed net current is zero; or if the magnetic field is zero; or when the magnetic field is normal to the path selected at any point.
- Ampere’s Law is useful in calculating the magnetic fields of current distributions with a high degree of symmetry.
BIOT SAVART LAW
The Biot-Savart Law is an equation that explains the magnetic field created by a current carrying wire, allowing the calculation of its strength at various points. This is because when a compass is moved near an electric wire, the compass needle tends to change the direction.