Heat treatment of muscular pain involves radiation of wavelength of about 900 nm. Which spectral line of Hatom is suitable for this purpose?
[RH = 1 × 105 cm–1, h = 6.6 × 10–34 Js, c = 3 × 108 ms–1]
(1) Balmer, x --->2
(2) Paschen, x ---> 3
(3) Lyman, ∞ ---> 1
(4) Paschen, 5 ---> 3
