Glossary
Biot-Savart Law
A fundamental law in electromagnetism that describes the magnetic field generated by an electric current, allowing calculation of the field at any point in space due to a current element.
Example:
Using the Biot-Savart Law, engineers can design precise electromagnets by calculating the magnetic field produced by complex wire configurations.
Current-carrying wire
A conductor through which electric charge is flowing, thereby generating a magnetic field around it.
Example:
When you turn on a light, the current-carrying wire inside the bulb's filament heats up and glows, simultaneously creating a magnetic field around it.
Magnetic Field
A region around a moving electric charge or a current-carrying conductor where magnetic forces are exerted on other moving charges or magnetic materials.
Example:
A compass needle aligns itself with the Earth's magnetic field, pointing towards the magnetic north pole.
Permeability of free space (μ₀)
A fundamental physical constant representing the ability of a vacuum to support the formation of a magnetic field, analogous to permittivity for electric fields.
Example:
The strength of the magnetic field produced by a solenoid in a vacuum depends directly on the permeability of free space, indicating how easily magnetic field lines can form.
Right-hand rule (for magnetic fields from currents)
A mnemonic 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 curled fingers indicate the direction of the magnetic field lines.
Example:
To determine which way a compass needle will point near a straight wire, you'd use the right-hand rule to find the direction of the magnetic field.
Unit vector (r̂)
A vector with a magnitude of one, used to specify direction without affecting the magnitude of another quantity.
Example:
In calculating gravitational force, the unit vector points from the center of one mass to another, indicating the direction of the force.