No. of lines produced when electron from nth shell drops to ground state
`Sigma (n_(2)-n_(1))=Sigma (6-1)= = Sigma 5=5+4+3+2+1=15`
There are produced due to following transitions :
`{:(6 rarr 5,5 rarr 4,4 rarr 3,3 rarr 2,2 rarr 1),(6 rarr 4,5 rarr 3,4 rarr 2,3rarr1,),(6 rarr 3,5 rarr 2,4 rarr 1,,),(6 rarr 2,5 rarr 1,,,),(6 rarr 1,,,,),(("5 lines"),("4 lines"),("3 lines"),("2 lines"),"(1 lines)"):}`
