As well as producing an electric field, charged particles will produce a magnetic field when they are in a state of motion that will be felt by other charges that are in motion (as well as permanent magnets). The direction of the force on a moving charge from a magnetic field is perpendicular to both the direction of motion and the direction of the magnetic field lines and can be found using the right-hand rule. The strength of the force is given by the equation F = q v B sin ⁡ ⁡ θ θ where F is the force on a charge q with speed v in a magnetic field B which is pointing in a direction of angle θ from the direction of motion of the charge.