The longest wavelength associated with Paschen series is
(Given RH=1.097×107 in SI unit) [2024]
(4)
For longest wavelength in Paschen's series:
1λ=R[1n12-1n22]
n1=3 and n2=4
1λ=R[1(3)2-1(4)2]=R[16-916×9]
⇒λ=16×97R=16×97×1.097×107=1.876×10-6m