If in Rutherford's experiment, the number of particles scattered at `90^(@)` angle are `28` per min, then number of scattered particles at an angle `60^(@)` and `120^(@)` will be

Options

A. 117 per minute, 25 per minute
B. 50 per minute, 12.5 per minute
C. 100 per minute, 200 per minute
D. 112 per minute, 12.4 per minute

Answer

D

Explanation

No . Of particles scattered through an angle
` theta = N (theta) = (k cancel(Z )^2)/( sin ^4 ((theta)/( 2)) (K.E .) ^2)`
` therefore 28 = ( 4 Kc z^2)/( (K.E)^2) for theta = 90 ^@ " " therefore (Kz^2 )/( (K.E )^2) = ( 28 )/( 4 ) = 7`
` therefore N ( 60 ^@ ) = (7 )/( sin ^4 ((60 ^@ )/(2)))=16 xx 7 = 112 // min`
`N ( 120^@) = ( 7 )/( sin ^4 ((120^@)/(2 )))=12.4 // min `