Ionized hydrogen atoms and `alpha-`particle with moments enters perpendicular to a constant megnetic field. B. The ratio of their radii of their paths `r_(H): r_(alpha)` be :

Options

A. `1 : 4`
B. `2 : 1`
C. `1 : 2`
D. `4 : 1`

Answer

B

Explanation

`r = (mv)/(qB) = (p)/(qB) implies r prop (1)/(q)`
`(r_(n))/(r_(alpha)) = (q_(alpha))/(q_(n)) = (2)/(1) = 2:1`