A charged particle of mass m and charge q moves with a constant velocity  v = a i along the positive x-direction. It enters a region of magnetic field which is directed towards positive z-direction, from x = l, which is given by B = b k and moves in a circular path.

Consider the following statements about the motion of the particle:

1. Force will always be perpendicular to the velocity.                           
2. The magnitude of the velocity remains constant.                                                           
3. Velocity vector and magnetic field vector remain perpendicular to each other during the motion.  
4. KE of the particle remains constant.       

Which of the following is true ?

All are true

All the given statements are hold correct.