6) You have already learnt in earlier classes (See Class XI,
Chapter 4) that if r is the radius of the circular path of a particle,
then a force of  m v2 / r, acts perpendicular to the path towards
the centre of the circle, and is called the  centripetal force If the
velocity v is perpendicular to the magnetic field   B, the  magnetic
force is  perpendicular to both v and B and acts
like a centripetal force It has a magnitude q v
B