Magnetism

• Fleming's left hand rule: thumb = force, middle = direction of current, index = direction of magnetic field
• Magnetic field lines go from north to south
• In diagrams a cross is for current going into the paper and a dot is for current going out of the paper
• A magnetic field is the result of a electrical current or a permenant stationary magnet
• The magnetic flux density is the strength of the magnetic field
• Magnetic flux density has the unit Tesla
• A velocity selector is a device that uses both electric and magnetic field to select a velocity of a charged particle
• Faraday's law is that the magnitude of the induced e.m.f is directly proportional to the rate of change of flux linkage
• Lenz's Law states that the direction of the induced e.m.f or current is opposite to the change producing it