Medium MCQ +4 / -1 PYQ · JEE Mains 2021

A nucleus with mass number 184 initially at rest emits an $\alpha$-particle. If the Q value of the reaction is 5.5 MeV, calculate the kinetic energy of the $\alpha$-particle.

  1. A 5.5 MeV
  2. B 5.0 MeV
  3. C 5.38 MeV Correct answer
  4. D 0.12 MeV

Solution

${k_\alpha } + {k_N} = 5.5$<br><br>$k = {{{p^2}} \over {2m}}$<br><br>$\Rightarrow {{{k_\alpha }} \over {{k_N}}} = {{180} \over 4} = 45$<br><br>$\Rightarrow {k_\alpha } = {{45} \over {46}} \times 5.5$ MeV<br><br>= 5.38 MeV

About this question

Subject: Physics · Chapter: Atoms and Nuclei · Topic: Radioactivity

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