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

A particle is travelling 4 time as fast as an electron. Assuming the ratio of de-Broglie wavelength of a particle to that of electron is 2 : 1, the mass of the particle is :

  1. A ${1 \over {16}}$ times the mass of e<sup>$-$</sup>
  2. B 8 times the mass of e<sup>$-$</sup>
  3. C 16 times the mass of e<sup>$-$</sup>
  4. D ${1 \over {8}}$ times the mass of e<sup>$-$</sup> Correct answer

Solution

$\lambda = {h \over p}$<br><br>$${{{\lambda _p}} \over {{\lambda _e}}} = {{{p_e}} \over {{p_p}}} = {{{m_e}{v_e}} \over {{m_p}{v_p}}}$$<br><br>$2 = {{{m_e}} \over {{m_p}}}\left( {{{{v_e}} \over {4{v_e}}}} \right)$<br><br>$\therefore$ ${m_p} = {{{m_e}} \over 8}$

About this question

Subject: Physics · Chapter: Dual Nature of Matter and Radiation · Topic: de Broglie Hypothesis

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