Magnetic effects

Section 1: Magnetic Fields

Introduction:
A moving charge or a chain of moving charges create a magnetic field around their path (velocity vector). Magnetic field is a vector so it has a magnitude and a direction. In introductory physics courses, we use some mathematical equations to find the magnitude of a magnetic field and right-hand rule for positive and electric current and left-hand rule for negative charges to find the direction of the magnetic field.

$\left | \vec{B} \right | = {{\mu_0} \over {4 \pi}} {|q|} {{|\vec{v}|}\over{d^2}} \sin{\theta_{\vec{v},\vec{d}}}$

where $\left | \vec{B} \right |$ is the magnitude of the magnetic field, $\mu_0$ is the permeability of the medium in henries per meter (H/m).

Following picture:

(Left) Right-hand rule for find the connection between direction of the motion (velocity) of a moving positive charge and the magnetic field it is generating.
(Right) Right-hand rule for finding the connection between direction of an electric current in a wire and the magnetic field it is generating.