A wire with a constant current lies in a uniform magnetic field. In which situation is the magnetic force on the wire zero?
Select one:
a. When the length vector is perpendicular to the magnetic field vector.
b. When the length vector is perpendicular to a magnetic field line.
c. The magnetic force can never be zero.
d. There is not enough information given to answer the question.
e. When the length vector is in the direction of the magnetic field vector.