CUET · PHYSICS · PYQ PAPER 2025
The relation below correctly represents the frequency of light emitted when an electron in a hydrogen atom jumps from a higher \( (n_i) \) energy level to \( (n_f) \) a lower energy level: \( \nu = Rc \left( \frac{1}{n_f^2} - \frac{1}{n_i^2} \right) \). Predict the values of \( n_i, n_f \), respectively for the Paschen series, which will give the highest wavelength in the series
- A 3, 2
- B 4, 3
- C 5, 4
- D \( \infty, 3 \)
Answer & Solution
Correct Answer
(B) 4, 3
Step-by-step Solution
Detailed explanation
\(n_f = 3\) (Paschen series) For highest \(\lambda\), lowest \(\nu\): \(n_i\) must be smallest integer \(> n_f\). \(n_i = n_f + 1 = 3 + 1 = 4\) \(n_i = 4, n_f = 3\)
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