If the series limit of Lymen series for Hydrogen atom is equal to the series limit of Balmer series for a hydrogen like atom, then atomic number of this hydrogen-like atomwill be

By using 1λ=RZ21n12−1n22  For hydrogen atom, 1λminH=R112−1∞=R ⇒λminH=1R.......(i)  For hydrogen like atom 1λminatom =RZ2122−1∞ ⇒ λminatom=4RZ2..........(ii)  From equations (i) and (ii),  1R=4RZ2 ⇒Z=2