Dual Nature, Atoms & Nuclei · JEE Main previous year questions

2014 1 question

1. Q582014 · 6 Apr 2014 · Shift 1

   Hydrogen (${}_1{\mathrm{H}}^1$), Deuterium (${}_1{\mathrm{H}}^2$), singly ionised Helium (${}_2{\mathrm{He}}^4$)${}^{+}$ and doubly ionised lithium (${}_3{\mathrm{Li}}^6$)${}^{++}$ all have one electron around the nucleus. Consider an electron transition from $n=2$ to $n=1$. If the wavelengths of emitted radiation are ${\lambda }_1,{\lambda }_2,{\lambda }_3$ and ${\lambda }_4$ respectively then approximately which one of the following is correct?

   1. A.$4{\lambda }_1=2{\lambda }_2=2{\lambda }_3={\lambda }_4$
   2. B.${\lambda }_1=2{\lambda }_2=2{\lambda }_3={\lambda }_4$
   3. C.${\lambda }_1={\lambda }_2=4{\lambda }_3=9{\lambda }_4$
   4. D.${\lambda }_1=2{\lambda }_2=3{\lambda }_3=4{\lambda }_4$
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   Answer: C