Changes

==Physics==

==Physics==

A solenoid can be very useful as the [[magnetic field]] it produces along its axis is uniform.<ref name=hyperphysics>[http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/solenoid.html Solenoid] from hyperphysics.phy-astr.gsu.edu</ref> Its overall magnetic if is very similar to that of a [[bar magnet]]. Its field can be strengthened by placing a ferromagnetic core composed of [[iron]] or [[steel]]. These contain magnetic [[domains], which act like tiny magnets and all align when put in an external magnetic field, increasing the overall field.

A solenoid can be very useful as the [[magnetic field]] it produces along its axis is uniform.<ref name=hyperphysics>[http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/solenoid.html Solenoid] from hyperphysics.phy-astr.gsu.edu</ref> Its overall magnetic if is very similar to that of a [[bar magnet]]. Its field can be strengthened by placing a ferromagnetic core composed of [[iron]] or [[steel]]. These contain magnetic domains, which act like tiny magnets and all align when put in an external magnetic field, increasing the overall field.

The field within the solenoid tends to be very uniform, while the surrounding field is normally extremely weak.<ref name=hyperphysics/> The field, ''B'', at the center of a solenoid is given by:<ref name=hyperphysics/>

The field within the solenoid tends to be very uniform, while the surrounding field is normally extremely weak.<ref name=hyperphysics/> The field, ''B'', at the center of a solenoid is given by:<ref name=hyperphysics/>