Electric current and magnetic field

Magnetic Field

Magnetic fields are produced by electric currents. The magnetic field B is defined in terms of force on moving charge in the Lorentz force law. Magnetic field sources are essentially dipolar in nature, having a north and south magnetic pole. The SI unit for magnetic field is the Tesla, which can be seen from the magnetic part of the Lorentz force law

Fmagnetic = qvB to be composed of (Newton x second)/(Coulomb x meter). A smaller magnetic field unit is the Gauss (1 Tesla = 10,000 Gauss).

where
V is velocity of the electric charge, measured in metres per second
X indicates a vector cross product
c is the speed of light measured in metres per second
E is the electric field measured in newtons per coulomb or volts per metre

Following Flash animation demonstrate the relation between current and magnetic field. Higher current will generate larger magnetic field.