Magnetic Fields

Magnetic fields- This is a reigon where forces act on charged particlesor magnetic materials

Magnetic fileds can be represented by field lines. These go from the north to the south poles of a magnet the closer the filed lines are the stronger the magnetic fileds

When there is a current in a wire a electric fild is present round the wire. To determine the direction of the magnetic field use flemmings right hand rule. This is where the thumb is the direction of current and the path of the persons fingers is the direction of field

When there is a wire in a magnetic filed (with current flowing through the wire) the wire will expearine a force. This is because the two magnetic fields add together which then produces filed lines which are colser on one side of the wire. So therefore there will be a stronger force in one dircetion than the other creating an overall resultant force. The direction could be determined using flemmings left hand rule. This is where the thumb is the force, the first finger is the external magnetic field and the second finger is the current The foce o the wire is propotional to the flux density shown by the equation F=Bil where B is the flux density(T), I is the current(A) and l is the length of the wire in the magnetic.

Tesla is also equal to Wb/m^2

The force on the wore is greatest when it is completly perpendicular to the fild lines which means that F=Bilsin can be used. If a where is completly parrell, there is no force

The equation F=Bil can also be rearranged into F=Bqv where B is flux density (T), q is the cahrge(C) and v is tbe velocity of the charged particles