Question on hydrogen line spectra

The atomic hydrogen emits a line spectrum consisting of various series. Which series of hydrogen atomic spectra is lying in the visible region ?

Among the first lines of Lyman, Balmer, Paschen and Brackett series in hydrogen atomic spectra which has higher energy?

The ratio of the largest to shortest wavelength in Balmer series of hydrogen spectra is,

The ratio of the longest to shortest wavelength in Brackett series of hydrogen spectra is

The hydrogen line spectrum provides evidence for the

The ratio of the largest to shortest wavelength in Lyman series of hydrogen spectra is