Question

In Rutherford's experiment the number of a-particles scattered through an angle of 90ŗ is 28 per minute. Then the number of particles scattered through an angle of 60ŗ per minute by the same nucleus is-

• A. 28 per minute
• B. 112 per minute
• C. 12.5 per minute
• D. 7 per minute

Answer 1

Answer: (B)

112 per minute

Answer 2

N_a µ $\frac{1}{\sin^{4}(\theta/2)}$

$\frac{N_{60º}}{N_{90º}} = \frac{\sin^{4}(45º)}{\sin^{4}(30º)} = \left( \frac{1/52}{1/2} \right)^{4} = 4$

N_60ŗ = 4 N_90ŗ = 4 × 28 = 112/min