Question

If wavelength of the first line of the Paschen series of hydrogen atom is _____ nm, then the wavelength of the second line of this series is nm (Nearest integer)

Answer 1

The correct answer is 492.
(λ1​)P​1​=RH​Z2(91​−161​)
(λ2​)P​1​=RH​Z2(91​−251​)
(λ1​)P​(λ2​)P​​=25×916​16×97​​=16×1625×7​
(λ2​)P​=16×1625×7​×720
(λ2​)P​=492nm