Which of the following series of transition in the spectrum of hydrogen atom fall in ultraviolet region?

The series of transitions in the spectrum of the hydrogen atom that falls in the ultraviolet region is the Lyman series.

Here's the step-by-step explanation:

1. The spectrum of the hydrogen atom is divided into a number of series, each corresponding to a different type of transition between energy levels. These series are named after their discoverers: Lyman, Balmer, Paschen, Brackett, and Pfund.

2. The Lyman series corresponds to transitions where the electron drops to the lowest (or ground) energy level, n=1.

3. The energy difference between the ground state and higher energy levels is quite large. When an electron makes a transition from a higher energy level to the ground state, it emits a photon with a high energy, which corresponds to a short wavelength.

4. The wavelength range of the Lyman series falls into the ultraviolet region of the electromagnetic spectrum. This is because ultraviolet light has shorter wavelengths (and hence higher energy) than visible or infrared light.

So, the series of transitions in the spectrum of the hydrogen atom that falls in the ultraviolet region is the Lyman series.