Magnetic Fields

Bar magnet - field lines go from north to south. Field lines show the direction of the force that a 'free' magnetic north pole would experience at that point, they are strongest when closest. Opposite poles repel causing a point that experience no field.

Solenoid carrying current - field lines curl round either side (north to south) with one field line going through the middle. Magnetic fields caused by moving charges (free electrons in a wire). The magnetic field around a current carrying wire is concentric circles at right angles with the wire.

Field direction - Right hand corkscrew rule = direction of the field lines in a long current carrying wire. Right hand grip rule (grip coil, thumb points in direction) - direction in magnetic field lines in a electromagnet.

Flemings Left hand rule for direction of the force on the current carrying conductor - thuMb = direction of motion , First finger = direction of Field, seCond finger - direction of…