Q.

Ionized hydrogen atoms and α-particles with same momenta enters perpendicular to a constant magnetic field, B. The ratio of their radii of their paths rH:rα will be    [2019]

1 1 : 4  
2 2 : 1  
3 1 : 2  
4 4 : 1  

Ans.

(2)

As, r=mvqB=pqB

For given p and B, r1q rHrα=qαqH=21