B-field

Definition

The B-field, or magnetic field, is a vector field that represents the influence of magnetic forces in a region. It is denoted by the symbol $\mathbf{B}$ and is measured in teslas (T).

5 Must Know Facts For Your Next Test

1. A B-field exerts a force on moving electric charges, described by the Lorentz force law: $\mathbf{F} = q(\mathbf{v} \times \mathbf{B})$.
2. Magnetic field lines form continuous loops from the north pole to the south pole of a magnet.
3. The strength of a B-field decreases with distance from the source, following an inverse square law for point sources.
4. Inside a solenoid, the B-field is uniform and parallel to the axis of the solenoid.
5. Earth has its own B-field, which protects us from solar wind and cosmic radiation.

Review Questions

• What is the unit of measurement for a B-field?
• How does a B-field interact with moving electric charges?
• Describe how magnetic field lines behave around a bar magnet.

Related terms

Lorentz Force:

The force exerted on a charged particle moving through an electric and magnetic field, given by $\mathbf{F} = q(\mathbf{E} + \mathbf{v} \times \mathbf{B})$.

Magnetic Flux:

The total magnetic field passing through a given area, calculated as $\Phi_B = \int \mathbf{B} \cdot d\mathbf{A}$.

Solenoid:

A coil of wire designed to create a uniform magnetic field inside its loops when an electric current passes through it.