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 out of the page due to its interation with the magnetic field ?
Positive charge.
→F=q(→V×→B);→V=−^j,→B=^i
→F=+q{−(−^k)}=+q^k;^k=pointingoutward
By fleming's right hand rule,
For the charged particle to come out of page the current should be flowing downwards. And the direction of current is in the direction of positive charge or the opposite of negative charge. Here the charge particle is going downwards and the current should also go down. Hence the particle is positively charged.