Fleming's Left hand rule - Motor Effect

A current carrying conductor experiences a force if it is placed in a magnetic field.  The direction of the force is found using Fleming's left hand rule. The force is proportional to: The current; The strength of the magnetic field ; The length of wire within the magnetic field. The formula relating the three quantities is:   F = BIl [B – magnetic field strength; I – current in A; l – length in m] The term B is called the magnetic field strength, or the flux density, and is measured in Tesla, T.  The magnetic flux density can be thought of as the concentration of field lines.   Example: A current of 8.5 A flowing through a magnetic field is found to exert a force of 0.275 N.  The length of wire in the magnetic field is 5 cm.  What is the value of the magnetic field?

Formula first:  F = BIl.

Þ B =  F  = ___0.275 N ___ = 0.647 T          Il       8.5 A ´ 0.05 m