A certain transition in H spectrum from an excited state to ground state in one or more steps gives rise to total 10 lines. How many of these belong to uv spectrum?

Number of special lines when an electronic transition occurs from higher level to first level =n(n-1)2=10n2 - n = 20n2 - n - 20 = 0n2 - 5n + 4n - 20 = 0n(n - 5) + 4(n - 5) = 0(n - 5)(n + 4) = 0n + 4 = 0n = -4 (impossible solution)n - 5 = 0n = 55 → 4, 5 → 3, 5 → 2, 5 → 1(UV-Region)           4 → 3, 4 → 2, 4 → 1(Vis-Region)                      3 → 2, 3 → 1(IR-Region)                                 2 → 1(IR-Region)