A proton, a neutron and an `alpha`-particle having thye same momentum, enters a region of uniform electric field between the parallel plates of a capacitor. The electric field is perpendicular to the initial path of the particles. Then the ratio of deflections suffered by them is

Options

A. `1:2:8`
B. `1:2:4`
C. `1:1:2`
D. None of these

Answer

(a)

Explanation

The deflection suffered by an charged particle in an electric field is ,
`y = qELD/m mu_(2) = qELD/(P^(2)/m)`
`y alpha qm/p^(2)`
`rArr y_(p):y_(d):y_(a) = q_(p)m_(p)/P_(p)^(2): q_(d)m_(d)/P_(d)^(2): q_(a)m_(a)/P_(a)^(2)`
`P_(a)=P(d)=P_(p)`
`m_(p):m_(d):m_(a) = 1 : 2 : 4`
`rarr y_(p):y_(d):y_(a) = 1 xx 1 : 1 xx 2: 2 xx 4 `
` = 1 : 2 : 8`