Question

A particle of mass m and charge q, moving with velocity V enters Region II normal to the boundary as shown in fig Region II has a uniform magnetic field B perpendicular to the plane of the paper The length of the Region II is Then

1. The particle enters Region III only if its velocity    
2. Path length of the particle in region II is maximum when velocity    
3. Time spent in Region II is same for any velocity V as long as the particle returns to Region I    
4. All the above are correct