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MHT CET 2023 (12 May, Shift 2) · Hydrogen Spectrum & Spectral Series

Hydrogen Spectrum & Spectral Series question from MHT CET 2023 (12 May, Shift 2)

Q31MHT CET 2023 · 12 MAY · SHIFT 2Medium

Hydrogen Spectrum & Spectral Series

In Balmer series, wavelength of the 22nd line is 'λ1\lambda_1' and for Paschen series, wavelength of the 11st line is 'λ2\lambda_2', then the ratio 'λ1\lambda_1 ' to 'λ2\lambda_2' is

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Answer: (c)

  1. Balmer 2nd line (4→24 \to 2): 1λ1=R(14−116)=3R16\frac{1}{\lambda_1} = R\left(\frac{1}{4} - \frac{1}{16}\right) = \frac{3R}{16}, so λ1=163R\lambda_1 = \frac{16}{3R}.
  2. Paschen 1st line (4→34 \to 3): 1λ2=7R144\frac{1}{\lambda_2} = \frac{7R}{144}, so λ2=1447R\lambda_2 = \frac{144}{7R}.
  3. λ1λ2=163×7144=727\frac{\lambda_1}{\lambda_2} = \frac{16}{3} \times \frac{7}{144} = \frac{7}{27}.
  4. So the answer is (c) 7:277 : 27.
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