If Rydberg's constant is R, the longest wavelength of radiation in Paschen series will be (α)/(7R), where α = ________. Numerical answer type. Work it out, then open the answer.

Answer: 144. Paschen longest ( 4 → 3): (1)/(λ) = R(1/9-1/16) = 7R/144 λ = 144/7R Answer: α = 144

If Rydberg's constant is R, the longest wavelength of radiation in… | JEE Main 2024 (27 Jan, Shift 2)

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Hydrogen Spectrum & Spectral Series

If Rydberg's constant is $R$ , the longest wavelength of radiation in Paschen series will be $\frac{\alpha}{7R}$ , where $\alpha =$ ________.

Numerical answer type. Work it out, then open the answer.

Show answer and solution

Answer: 144

Paschen longest ( $4 \to 3$ ): $\frac{1}{\lambda} = R\left(\frac{1}{9}-\frac{1}{16}\right) = \frac{7R}{144}$
$\lambda = \frac{144}{7R}$
Answer: $\alpha = 144$