The Lyman series occurs between 91.2 nm and 121.6 nm , the Balmer series occurs between 364.7 nm and 656.5 nm and the Paschen series occurs between 820.6 nm and 1876 nm, Identify the spectral regions to which these wavelengths correspond .

The only e^- in the H-atom resides under ordinary conditions on the first orbit when energy is supplied, the e^- moves to higher energy shells depending upon the amount of energy absorbed. When an e emits energy i.e., the e^- returns to the lowest energy state, from this Lyman, Balmer, Paschen, Bracket, Pfund series are there, so different spectral lines in the spectra of atoms correspond to different transitions of e^- s from higher to lower energy levels: The ratio of number of spectral lines obtained when an e^- s jumps from 7^(th) to ground to 6^(th) to 3^(rd)

Interference fringes are obtained in a Young's double slit experiment using beam of light consisting two wavelengths 500 nm and 600 nm. Bright fringes due to both wavelengths coincide at 2.5 mm from the central maximum. If the separation between the slits is 3 mm, then the distance between the screen and plane of the slits is

(A) : Limiting line in Balmer series has a wavelength of 364.4 nm (R) : Limiting line is obtained when electron jump from n = oo orbit