Exam

JEE Advanced

Year

2008

Paper

Paper 1

Subject

Physics

Chapter

Atomic Physics

JEE Advanced 2008 · Paper 1 · Physics · Atomic Physics

Paragraph: In a mixture of H-H^ + gas (He^ + . is singly ionised He...

Paragraph: In a mixture of $\mathrm{H}-\mathrm{H}^{+}$gas \left(\mathrm{He}^{+}\right.$is singly ionised$\mathrm{He}$atom),$\mathrm{H}$atoms and$\mathrm{He}^{+}$ions are excited to their respective first excited states. Subsequently,$\mathrm{H}$atoms transfer their total excitation energy to$\mathrm{He}^{+}$ions (by collisions). Assume that the Bohr model of atom is exactly valid.<strong>Question:</strong> The quantum number$n$of the state finally populated in$\mathrm{He}^{+}ions is

Step-by-step solution

Energy given by $\mathrm{H}$-atom in transition from $n=2$ to $n=1$ is equal to energy taken by $\mathrm{He}^{+}$ atom in transition from $n=2$ to $n=4$. $\therefore$ correct option is (c).