Correct Answer: 54
For hydrogen atom, energy of emitted photon is given by
\[ E = 13.6\left(\frac{1}{n_1^2}-\frac{1}{n_2^2}\right)\ \text{eV} \]
Energy of L1 (Lyman series):
For Lyman series, transitions end at \(n_1 = 1\).
For L1, the transition is from \(n_2 = 2 \to n_1 = 1\).
\[ E_{L_1} = 13.6\left(1-\frac{1}{4}\right) \]
\[ E_{L_1} = 13.6 \times \frac{3}{4} \]
\[ E_{L_1} = 10.2\ \text{eV} \]
Energy of B1 (Balmer series):
For Balmer series, transitions end at \(n_1 = 2\).
For B1, the transition is from \(n_2 = 3 \to n_1 = 2\).
\[ E_{B_1} = 13.6\left(\frac{1}{4}-\frac{1}{9}\right) \]
\[ E_{B_1} = 13.6 \times \frac{5}{36} \]
\[ E_{B_1} \approx 1.89\ \text{eV} \]
Ratio of energies:
\[ x = \frac{E_{L_1}}{E_{B_1}} = \frac{10.2}{1.89} \approx 5.4 \]
\[ x = 54 \times 10^{-1} \]
Hence, the required value of x = 54.
Updated for JEE Main 2026: This PYQ is important for JEE Mains, JEE Advanced and other competitive exams. Practice more questions from this chapter.