The flux of `alpha-`particle at `2^@` is `1 xx 10^6`. The flux of `alpha-`particle at angle `60^@` is

Options

A. 5.5
B. 2.5
C. 0.5
D. 1.5

Answer

D

Explanation

(d) Rutherford on this basis of Coulomb's law calculated the number of particles scattered at different angles and found that the number of particles `N` scattered at angle `theta` are related as follows
`N prop (1)/(sin^4 theta//2)`
`(N_(60^@))/(N_(2^@)) = (sin^4(1^@))/(sin^4(30)) = ((0.0175))/(((1)/(2))^4)`
`rArr (N_(60^@))/(N_(2^@)) = 1.5 xx 10^-6`
`N_(60^@) = 1.5 xx 10^-6 xx 10^6`
`N_(60^@) = 1.5`.