The longest wavelength associated with Paschen series is: (Given RH = 1.097 × 10⁷ SI unit) (a) 2.973 × 10⁻⁶ m (b) 1.876 × 10⁻⁶ m (c) 1.094 × 10⁻⁶ m (d) 3.646 × 10⁻⁶ m

Answer: (b). Paschen longest ( 4 → 3): (1)/(λ) = R(1/9-1/16) = 7R/144 λ = 1447× 1.097× 10⁷ λ ≈ 1.876× 10⁻⁶ m So the answer is (b) 1.876 × 10⁻⁶ m.

The longest wavelength associated with Paschen series is: (Given RH =… | JEE Main 2024 (6 Apr, Shift 2)

Q23JEE Main 2024 · 6 APR · SHIFT 2Medium

Hydrogen Spectrum & Spectral Series

The longest wavelength associated with Paschen series is: (Given $R_H = 1.097 \times 10^{7}\text{ SI}$ unit)

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Answer: (b)

Paschen longest ( $4 \to 3$ ): $\frac{1}{\lambda} = R\left(\frac{1}{9}-\frac{1}{16}\right) = \frac{7R}{144}$
$\lambda = \frac{144}{7\times 1.097\times 10^{7}}$
$\lambda \approx 1.876\times 10^{-6}$ m
So the answer is (b) $1.876 \times 10^{-6}$ m.