Unfortunately, there is nothing much about technique in this problem. Full-range quantum mechanics might not be helpful too since you may not solve the Schrodinger's equation on time. However, if you vaguely remember Bohr's theory of atom and transition spectrum of hydrogen (Lyman, Balmer, etc.). You might remember that there are many lines corresponds to energy levels. The lines gets closer and closer in the diagram at the top, where
is large. If you notice this, you can eliminate (A), (B), and (D) since they all represents energy levels which spread out when
is large. Now, for (C), it is not natural to have
in there since if
, the energy blows up (you should know that 2 should be a good number of principle quantum number). The only choice you have now is (E).
This is an example that, even if you have just a small detail in your mind, you can do the exam without any calculation.
The correct answer is (E). 64 of 100 people got it correct.
ฟิสิกส์โอลิมปิก วิทยาศาสตร์โอลิมปิก ข้อสอบแข่งขัน ข้อสอบชิงทุน
