AP EAPCET 25-Aug-2021 Shift 1 Paper

Sequence of series in hydrogen spectrum are Lyman series (n=1), Balmer series (n=2), Paschen series (n=3), Bracket series (n=4) and Pfund series (n=5).
For Lyman series, n1=1
For shortest wavelength in Lyman series i.e., the energy difference in two states showing transition should be maximum i.e., n2=∞
Using formula,

1

λ

=RH[

1

n12

−

1

n22

]
hereRH=Rydberg‌constant

1

λ

=RH[

1

12

−

1

∞2

]
⇒

1

λ

=RH
λ=

1

RH

=

1

109678

=9.117×10−6‌cm=91.2‌nm
Hence, Lyman series is a spectral series of transitions and resulting ultraviolet emission lines of H-atom.