Glossary
Biot-Savart Law
A fundamental law that describes the magnetic field produced by an electric current, allowing for the calculation of the magnetic field generated by a small segment of a current-carrying wire.
Example:
Using the Biot-Savart Law, engineers can design electromagnets by precisely calculating the magnetic field produced by complex coil geometries.
Force on Current-Carrying Wires
The phenomenon where a wire carrying electric current experiences a force when placed within an external magnetic field.
Example:
The operation of an electric motor relies on the force on current-carrying wires within a magnetic field, causing rotation.
Magnetic Field Calculations
The process of applying laws like the Biot-Savart Law and principles of symmetry to determine the magnitude and direction of magnetic fields produced by various current configurations.
Example:
Performing magnetic field calculations for a solenoid helps determine its effectiveness as an electromagnet in a particle accelerator.
Magnetic Field Vectors
Arrows used to represent the direction and magnitude of a magnetic field at various points in space, always tangent to concentric circles around a current-carrying wire.
Example:
When mapping the magnetic field around a straight wire, the magnetic field vectors would form circles around the wire, with their direction given by the right-hand rule.
Magnetic Fields of Current-Carrying Wires
The region around a wire through which electric current flows, where magnetic forces can be observed and measured.
Example:
A compass needle deflects when brought near a magnetic field of a current-carrying wire, indicating the presence of a magnetic field.
Magnetic Force on Wires
The specific force exerted on a segment of a current-carrying wire when it is immersed in an external magnetic field, calculated using a cross product.
Example:
If a power line sways in Earth's magnetic field, the magnetic force on wires might be negligible, but in a strong laboratory magnet, it could be significant.
Permeability of free space (μ₀)
A fundamental physical constant representing the ability of a vacuum to permit magnetic field lines to pass through it, used in equations like the Biot-Savart Law.
Example:
The strength of a magnetic field generated by a current in a vacuum is directly proportional to the permeability of free space (μ₀).
Right-Hand Rule (for force)
A mnemonic rule used to determine the direction of the magnetic force on a current-carrying wire: point fingers in current direction, curl towards magnetic field, and thumb points in force direction.
Example:
When designing a speaker, understanding the Right-Hand Rule (for force) is crucial to ensure the voice coil moves in the desired direction to produce sound.
Right-Hand Rule (for magnetic field)
A mnemonic rule used to determine the direction of the magnetic field around a current-carrying wire: point your thumb in the direction of the current, and your fingers curl in the direction of the magnetic field.
Example:
To find the direction of the magnetic field above a wire carrying current to the right, you'd use the Right-Hand Rule (for magnetic field), pointing your thumb right, and your fingers would curl out of the page.