(i)
It depends on q, v and B (charge of the particle, the velocity and the
magnetic field) Force on a negative charge is opposite to that on a
positive charge (ii) The magnetic force q [ v × B ] includes a vector product of velocity
and magnetic field The vector product makes the force due to magnetic
HENDRIK ANTOON LORENTZ (1853 – 1928)
Hendrik Antoon Lorentz
(1853 – 1928) Dutch
theoretical 
physicist,
professor at Leiden