In a certain electronic transition from the quantum level, 'n' to the ground state in atomic hydrogen in one or more steps, no line belonging to the Brackett series is observed. What wave numbers may be observed in the Balmer series? (R=Rydberg Constant)

No line belonging to Brackett series means n2 ≤ 4Thus n2 can be 4, 3, 2Possible transitions are 4 → 3, 4 → 2, 4 → 1, 3 → 2, 3 → 1, 2 → 1Lines belonging to Balmer series are 4 → 2 & 3 → 2For the electronic transition 4 → 2, v¯=1λ=RH12122-142   =3RH16For the electronic transition 3 → 2,v¯=1λ=RH12122-132=5RH36