Question

In Balmer series of lines of hydrogen spectrum, the third line from the red end corresponds to which one of th e following inner orbit jumps of the electron for bohr orbits in an atom of hydrogen?

A.3->2

B. 5->2

C. 4->1

D. 2->5

Answer 1

Since the line in hydrogen spectrum lies within visible region that is at red end, therefore it is corresponds to the Balmer series.
The line at the red end suggests that
The first line of Balmer series is n = 3 to n =2
The second line of Balmer series is n = 4 to n = 2
The third line of Balmer series is n = 5 to n = 2

Thus answer is (2)
5 → 2