A-level Physics/Electrons and Photons/Magnetic effects of current
Fleming's left hand rule
Use your thumb, first and second fingers to point at 90° to each other: like the corner of a box.
First finger: Field
seCond finger: Current
THumb: THrust
Formula
F is the force produced, measured in newtons. B is the magnetic field strength (flux density), measured in Tesla. I is the current that the magnetic field is acting on, measured in Amps. L is the length of the electrical wire, measured in metres.