Magnetic field strength inside a solenoid

Definition

Magnetic field strength inside a solenoid is the intensity of the magnetic field created within a coil of wire when an electric current passes through it. It is uniform and parallel to the axis of the solenoid.

5 Must Know Facts For Your Next Test

1. The magnetic field strength inside a solenoid is given by $B = \mu_0 n I$, where $B$ is the magnetic field, $\mu_0$ is the permeability of free space, $n$ is the number of turns per unit length, and $I$ is the current.
2. Inside a long solenoid, the magnetic field strength is uniform and does not depend on the position along its length.
3. $\mu_0$, the permeability of free space, has a value of approximately $4\pi \times 10^{-7} \, \text{T} \, \text{m/A}$.
4. The direction of the magnetic field inside a solenoid follows the right-hand rule: if you curl your fingers in the direction of current flow through the coils, your thumb points in the direction of the magnetic field.
5. Increasing either the current ($I$) or the number of turns per unit length ($n$) will increase the magnetic field strength inside a solenoid.

Review Questions

Related terms

Permeability:

A measure of how easily a material can support an external magnetic field. In vacuum or air, this constant is denoted as $\mu_0$.

Ampere's Law:

$\oint B \cdot dl = \mu_0 I_{enc}$; This law relates integrated magnetic fields around closed loops to electric currents passing through those loops.

Right-Hand Rule:

A mnemonic for understanding orientation conventions for vectors in three dimensions related to electromagnetic phenomena. Used to find directions of fields and forces.