If the wire has an arbitrary shape we can calculate the Lorentz force
on it by considering it as a collection of linear strips dlj and summing
j
j
Id
×
F 
B
l
This summation can be converted to an integral in most cases FIGURE 4 2 The direction of the magnetic
force acting on a charged particle (a) The
force on a positively charged particle with
velocity v and making an angle q with the
magnetic field B is given by the right-hand
rule