Question

A charged particle enters at right angles into a uniform magnetic field as shown: 

 

What should be the nature of charge on the particle if it begins to move in a direction pointing vertically our of the page due to its interaction with the magnetic field?  

Answer 1

The charge is positive in nature. On applying Fleming's left-hand rule, we find that only positive charge will experience a force pointing vertically outwards due to its interaction with the magnetic field.