The following applet show interaction force between a circular current loop in magnetic field generated by a magnet.
Red arrow show the direction of the current.
Blue arrow are force $\vec{F}=i d\vec{\ell}\times \vec{B}$ due to current loop in magnetic field generated by a magnet.

You can change the location of magnet with two sliders (move in y/z direction).
The radius R of the current loop can be changed with slider,too.
Click play to trace out the magnetic field lines (produced by magnet).

/htdocs/ntnujava/ejsuser/2/users/ntnu/fkh/magnetNcoil_pkg/magnetNcoil.propertiesFull screen applet or Problem viewing java?Add http://www.phy.ntnu.edu.tw/ to exception site list