In Rutherford's `alpha` particle experiment with thin gold foil, 8100 scattered `alpha`-particles per unit area per unit area per minute were observed at an angle of `60^(@)`. Find the number of scattered `alpha` particles per unit area per minute at and angle of `120^(@)`

Options

A. 900
B. 2025
C. 32400
D. 4050

Answer

A

Explanation

Number of `alpha`-particles scattered through angle `theta`
`Nprop(1)/(sin^(4)((theta)/(2))) or (N_(1))/(N_(2))=(("sin"^(4)(theta_(2))/(2)))/(("sin"^(4)(theta_(1))/(2)))`
or `(8100)/(N_(2))=(("sin"^(4)(120)/(2)))/(("sin"^(4)(60)/(2))) or (8100)/(N_(2))=(sin^(4)60)/(sin^(4)30)`
`implies N_(2)=(8100xx(1)/(16))/((9)/(16)) or N_(2)=900`