NEET Class neet Answered

Qn. # 8.

In Geiger-Marsden experiment , impact parameter is zero for head-on collision.

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Qn. # 9

Trajectory of α-particle depends on impact parameter

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Qn. #10

In Giger-Marsden experiment , distance d of closest approach of α-paricle from gold nucleus is calculated

by equating its kinetic energy to the potential energy of alpha particle at closest approach distance

  .......................... (1)

LHS of above expression is potential energy.

where K = 1/(4πε_o ) = 9 × 10⁹ N m² C^-2 is Coulomb's constant, e = 1.602 × 10^-19  C  is unit charge ,

Z= 79  is atomic number of gold nucleus and d is distance of closest approach .

From eqn.(1) , we get

Hence we get closest approach as 47 fm

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