question_answer

The trajectories, traced by different \[\alpha \]-particles, in Geiger-Marsden experiment were observed as shown in Fig. What names are given to the symbols \['b'\] and \['\upsilon '\] shown here? What can we say about the values of \['b'\] for (i) \[\theta \simeq 0\overset{\circ }{\mathop{\text{A}}}\,\] and (ii) \[\theta \simeq \pi \]radians?                

Answer:

                The symbol \['b'\] represents impact parameter and \['\theta '\] represents the scattering angle. (i) When\[\theta ={{0}^{\circ }}\], the impact parameter b is large and the \[\alpha \]-particle passes almost undeflected. (ii) When \[\theta \simeq \pi \] n radians, the impact parameter b = 0 and the \[\alpha \]-particle is reversed back along its original path.