Hydrogen Spectra

Which of the following series of transitions in the spectrum of hydrogen atoms falls in the visible region?

1. Brackett series

2. Lyman series

3. Balmer series

4. Paschen series

If radius of second Bohr orbit of the ion is 105.8 pm, what is the radius of third Bohr orbit of ion?

1.	158.7 Å	2.	158.7 pm
3.	15.87 pm	4.	1.587 pm

The ratio of the wavelengths of the light absorbed by a Hydrogen atom when it undergoes and
transitions, respectively, is

1.		2.
3.		4.